U.S. Department of Justice
Office of Justice Programs
Bureau of Justice Statistics

June 2014

Special Reportncj 245959

Seasonal Patterns in Criminal
Victimization Trends
Janet L. Lauritsen, Ph.D., BJS Visiting Fellow, and Nicole White, Ph.D., University of Missouri – St. Louis

Introduction
Seasonal patterns exist when similar fluctuations in thevictimization rates tend to recur each year during the same
season. Seasonal patterns are a long-standing topic in both
popular and scholarly literatures on crime and show how
environmental factors, such as temperature changes anddaylight hours, might be associated with crime throughout
the year. Seasonal patterns also are examined to learn
whether routine activity patterns, such as those associatedwith the beginning and end of the school year, are associatedwith variations in crime throughout the year.
This report examines seasonal patterns in violent andhousehold property victimization in the United States from1993 to 2010. It describes seasonal patterns for householdproperty victimization (burglary, motor vehicle theft, andhousehold larceny) and types of violence (rape and sexualassault, robbery, aggravated assault, and simple assault).
Trends in other forms of violence, including intimate partner
violence, victimizations involving weapons, and thoseresulting in injury, also are examined to determine the extent
to which seasonal fluctuations exist.

For household property crimes, the victimization data
indicate that there are seasonal patterns in householdburglary and larceny, with higher rates in the summer andlower rates during other seasons of the year. Motor vehicle
thefts do not exhibit the same seasonal patterns.
For violent victimizations, seasonal patterns also varydepending on the type of crime. Rape and sexual assault
rates and aggravated assault rates are higher in the summer
than in most other seasons. In comparison, simple assault
rates are higher in the fall than in other seasons, and robbery
victimization rates show no seasonal patterns. Intimate
partner violence exhibits regular seasonal fluctuations with
rates highest during the summer and lowest during thewinter. Rates of violence involving weapons and violence
resulting in serious injury are higher in the summer than in
the winter and spring seasons; however, the fall rates are notsignificantly different from the summer rates.

Highlights
 When seasonal variations in household property

victimization were found, the differences between thehighest and lowest seasonal rates were less than 11%.
 Seasonal patterns existed in household larceny and burglary

victimization rates. Rates of these household crimes tended
to be higher in the summer than during other seasons of
the year.
 Though rates of motor vehicle theft tended to be lower

in the spring than in the summer, there were few regulardifferences between summer, fall, and winter rates.

 Aggravated assault rates were higher during the summer

than during the winter, spring, and fall. In comparison,
simple assault rates were higher during the fall than duringother seasons of the year.
 Robbery rates did not exhibit seasonal variations.
 Rape and sexual assault victimization rates tended to behigher during the summer than during the fall and winter.
 Rates of intimate partner violence were higher during thesummer than during the winter, spring, and fall.

 When seasonal variations were found for violent

victimization, the differences between the rates of thehighest and lowest season were less than 12%.

BJSThe data in this report were developed from the Bureauof Justice Statistics’ (BJS) National Crime Victimization
Survey (NCVS), which annually collects information on
nonfatal victimizations against persons age 12 or older
from a nationally representative sample of U.S. households.
The data included crimes reported and not reported to thepolice from 1993 to 2010. Asking the victim in which month
the incident occurred makes it possible to assess how therisk for victimization varies throughout the year. For eachof the crime types, differences in the rates are comparedacross the four seasons of the year. Winter rates are basedon victimizations that occur in December, January, andFebruary; spring rates occur in March, April, and May;
summer rates occur in June, July, and August; and fall rates
occur in September, October, and November. Seasonalpatterns in the 1993 to 2010 trends exist when statisticalanalyses reveal periodic fluctuations in the rates, which tend
to recur each year during the same season See Methodology
for a description of the statistical analysis used in this report.

Prior BJS Research on Seasonality
BJS has previously examined seasonal patterns inselected types of victimization using monthly data from1973 to 1977 from the National Crime Survey (NCS), thepredecessor of the National Crime Victimization Survey(NCVS).1 Earlier research examined some of the same typesof victimizations assessed in this report.
The previous report found notable seasonal fluctuations
in household larceny and burglary, and rates werehighest during the summer months. Seasonal differenceswere also found for motor vehicle theft and for assault
victimization. For these crimes, the differences between
the summer and winter month rates were relatively
smaller than those found for household burglary andlarceny. The earlier findings for these types of victimization
are similar to the patterns shown in this report; however,
the magnitude of the seasonal differences were somewhat
larger from 1973 to 1977 than from 1993 to 2010. During
the earlier period, burglaries were about 26% less frequentin the winter than in the summer, while in the more recent
period, the winter versus summer difference in burglary
was about 11%. No significant seasonal fluctuations were
found for robbery in either study.
1Crime and Seasonality: National Crime Survey Report, NCJ 64818,
BJS web, May 1980.

BJS Visiting Fellows
The BJS Visiting Fellows program is intended to facilitate
collaboration between academic scholars and government
researchers in survey methodology, statistics, economics,
and social sciences. Visiting Fellows have the unique
opportunity to address substantive, methodological, andanalytic issues relevant to BJS programs, and to further
knowledge and understanding of criminal justice systems
operation. Fellows conduct research at BJS or at theirhome site, use BJS data and facilities, and interact with BJS
staff. Pending available funding, the program is normallyconducted each year through a competitive solicitation.

Seasonal patterns in Criminal Victimization Trends | June 2014

Applicants are limited to senior-level social science
researchers or statisticians in the fields of statistics, survey
methodology, mathematics, criminology, demography,
economics, behavioral science, and other related fields.
They must have an established research record in theirfield, have considerable expertise in their area of proposed
research, and be willing to commit a substantial portion of
their time (typically 6 to 18 months) to undertake analysesof existing BJS data. In addition, they must produce areport that both summarizes their analyses and meets
BJS publication and data quality standards. For further
information, see http://www.bjs.gov/content/fellows.cfm.

2

Seasonal patterns in householdproperty victimization
Total household property victimization
Rates of total household property victimization include
burglary, motor vehicle theft, and household larceny.
Differences in the total household property victimization
rates across winter, spring, summer, and fall exhibitedrecurrent seasonal patterns (figure 1). In all of the years
except 1995, rates of household property victimization
appeared highest in summer and lowest in either winter or
spring. Statistical analysis of the seasonal rates indicates thatthey were higher in the summer than in the other seasonsof the year (table 1). Compared to summer rates, householdproperty victimization rates were an average of about

7% lower in winter, 8% lower in spring, and 3% lower in fall.
Therefore, the difference between rates in the summer andother seasons was relatively small.
Table 1
Average percent difference in seasonal rate of household
victimization, by type of crime, 1993–2010
WinterSpringSummerFall

Total property
crime-6.9%*
-8.0*
~
-3.1*

Householdburglary-10.5%*
-8.8*
~
-5.9*

Motor
vehicle theft
-2.2%
-5.6*
~
0

Householdlarceny-6.4%*
-8.0*
~
-2.7*

Note: See appendix table 1 for regression coefficients and standard errors.
*Difference is statistically significant (p < .05, two-tail test).
~Highest rate season used for percentage comparisons.
Source: Bureau of Justice Statistics, National Crime Victimization Survey,
1993–2010.

Figure 1
Seasonal rates of household property victimization, 1993–2010
Per 1,000 households
100

80

60

40

Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

0Winter '93
Summer '93

20

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 20143

Burglary
Household burglary exhibited seasonal patterns, with rates
of victimization typically highest in summer and lowest in
winter or spring (figure 2). In all but 3 years (1999, 2005,
and 2008), rates of burglary appeared2 highest in summer.
2The term "appeared" refers to within year seasonal variations in point
estimates that are not statistically different.

In some years, spring rates of burglary were lower thanwinter rates. On average, household burglary rates wereapproximately 11% lower in winter, 9% lower in spring, andabout 6% lower in fall than in summer. Among householdproperty crimes, burglary showed the largest average
difference (11%) between the peak (summer) and trough(winter) seasonal rates.

Figure 2
Seasonal rates of burglary, 1993–2010
Per 1,000 households
20

15

10

5

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

0

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 2014

4

Motor vehicle theft
Compared to other household property crimes, rates ofmotor vehicle theft showed limited amounts of seasonalvariation from 1993 to 2010 (figure 3). In approximately
half of the years, motor vehicle theft appeared highest in thesummer, while in other years it appeared higher during thefall. The lowest rates of motor vehicle theft seemed to be in

the spring, though this was not always the case. Statisticalanalysis confirmed the lack of seasonality in motor vehicle
theft and revealed that the differences between summer, fall,
and winter rates were not statistically significant. However,spring rates were significantly lower than summer rates
of motor vehicle theft, with spring rates on average about
6% lower than summer rates.

Figure 3
Seasonal rates of motor vehicle theft, 1993–2010
Per 1,000 households
10

8

6

4

0

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

2

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 20145

Household larceny
Rates of household larceny showed some consistent seasonal
fluctuations throughout the 1993 to 2010 period (figure 4).
Household larceny typically appeared highest in thesummer, though in some years (such as 1994 to 1996), fall
rates appeared equal to or slightly higher than the summer

rates. Like burglary, household larceny rates also appeared to
be lowest in the spring or winter. Statistical analyses revealed
seasonality in household larceny. Compared to summer
rates, household larceny rates were about 6% lower in thewinter, 8% lower in spring, and about 3% lower in fall.

Figure 4
Seasonal rates of household larceny, 1993–2010
Per 1,000 households
80

60

40

20

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

0

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 20146

Seasonal patterns in violent
victimization
Total violent victimization
Summary indicators and specific types of violence were
examined to assess the seasonal patterns for violent
victimization. Total violent victimization includes rapeand sexual assault, robbery, aggravated assault, and simple
assault. Differences in the total violent victimization rates
across the winter, spring, summer, and fall exhibited somerecurrent seasonal patterns from 1993 to 2010 (figure 5).
However, these patterns were different from those observedfor household property victimization.
In most years, rates of violence appeared highest in thefall and lowest in the winter, though this was not always
the case. On average, statistical analysis indicated that therates were higher in the fall than in the winter and spring

and that summer rates were statistically similar to rates ofviolence during the fall (table 2). Though the differences
between the fall rates of violence and the winter and spring
rates were statistically significant, the seasonal variations
were small. On average, rates of violence during the fall wereabout 4% higher than winter rates and about 3% higher thanspring rates.
Table 2Average percent difference in seasonal rate of violent
victimization, by type of crime, 1993–2010
WinterSpringSummer
Fall

Total
Serious Rape/sexual
Aggravated Simple
violence violence assault
Robbery assault
assault-4.4%* -5.6%*-9.0%*-2.5%-6.9%*-5.6%*
-3.4*
-4.7*
-6.0
-1.9
-6.0*
-4.7*
-1.8
~
~
-0.6
~
-5.0*
~
-3.2*
-10.4*~-3.6*~

Note: See appendix table 2 for regression coefficients and standard errors.
*Difference is statistically significant (p < .05, two-tail test).
~Highest rate season used for percentage comparisons.
Source: Bureau of Justice Statistics, National Crime Victimization Survey,
1993–2010.

Figure 5
Seasonal rates of total violent victimization, 1993–2010
Per 1,000 persons age 12 or older
20

15

10

0

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

5

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 2014

7

Serious violent victimization
Serious violent victimization rates, which include rapeand sexual assault, robbery, and aggravated assault, varied
significantly across the seasons in ways that differed fromthose for total violent victimization (figure 6). Statisticalanalysis of seasonal rates showed that serious violence wassignificantly higher during the summer than during thewinter, spring, and fall seasons. Winter rates of serious

violence were approximately 6% lower on average thansummer rates of serious violence, and rates for spring(5% lower) and fall (3% lower) were also lower than summer
rates. Because serious violent victimization excluded simple
assault, the differences between the seasonal patterns for
total and serious violent victimization indicate a uniqueseasonal pattern for simple assault victimization comparedto other types of violence.

Figure 6
Seasonal rates of serious violent victimization, 1993–2010
Per 1,000 persons age 12 or older
10

8

6

4

0

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

2

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 20148

Rape and sexual assault
When trends in specific types of violent crime were
examined separately, differences in seasonal patterns
emerged. Rape and sexual assault rates exhibited someregular fluctuation across some of the seasons; however,the patterns did not indicate a single peak season, as thedifferences between the summer and spring rates were notstatistically significant (figure 7). Winter and fall rates ofrape and sexual assault tended to be lower than summer
rates, but they were not significantly lower than spring rates.
From 1993 to 2010, winter rates of rape and sexual assault
were approximately 9% lower on average than summer rates,
and fall rates were about 10% lower than summer rates.

Figure 7
Seasonal rates of rape and sexual assault, 1993–2010
Per 1,000 persons age 12 or older
1.0

0.8

0.6

0.4

0.0

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

0.2

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 20149

Robbery
Unlike the other types of violent crime, robbery did notexhibit seasonal fluctuations from year to year (figure 8).
Robbery victimization rates were statistically similar during

winter, spring, summer, and fall. This similarity in seasonalrates indicates that the periodic fluctuations that wereobserved in the rates did not usually recur each year during
the same season.

Figure 8
Seasonal rates of robbery, 1993–2010
Per 1,000 persons age 12 or older
2.0

1.6

1.2

0.8

0.0

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

0.4

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 201410

Aggravated assault
Seasonal patterns in aggravated assault were statisticallysignificant and most comparable to those shown for serious
violent victimization (figure 9). This was because aggravatedassault rates were higher than the rates for the other serious
violence crime types (rape and sexual assault and robbery).
In over half of the years, aggravated assault appeared to peakin the summer. Likewise, the seasonality analysis indicatedthat aggravated assault rates were significantly higher during
the summer than during the winter, spring, and fall seasons.
More specifically, winter rates of aggravated assault wereabout 7% lower on average than summer rates, and rates forspring (6% lower) and fall (4% lower) were also lower thansummer rates.

Figure 9
Seasonal aggravated assault rates, 1993–2010
Per 1,000 persons age 12 or older
5

4

3

2

0

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

1

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 201411

Simple assault
As suggested by the differences in the seasonal patterns
for total violence and serious violent victimization, simple
assault rates exhibited a unique pattern of seasonality(figure 10). Unlike any other type of violent victimization,
simple assault rates were highest in the fall. On average,

winter rates of simple assault were nearly 6% lower thanfall rates, while spring and summer rates were about 5%
lower than fall rates. This unique seasonal pattern for simple
assault was due to the experiences of youth ages 12 to 17
whose victimization experiences exhibited distinct seasonalpatterns compared to adults (see textbox on page 13).

Figure 10
Seasonal rates of simple assault, 1993–2010
Per 1,000 persons age 12 or older
10

8

6

4

0

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

2

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 201412

Seasonal patterns in simple assault differed for youth and adults
Simple assault victimization rates were higher among youth ages 12 to 17 than among adults age 18 and older andexhibited different peak and trough seasons (figure 11). Simple assault rates among youth were lowest during the summer
when the school year ended, and highest in the fall when the school year began. Adult rates of simple assault exhibited
relatively less seasonal fluctuation and were highest in the summer.

Figure 11
Seasonal rates of simple assault for youth and adults, 1993–2010
Per 1,000 persons age 12 or older
35
30
25
20
15
10
Age 12–17
5
Age 18 and older
Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

0

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 201413

Intimate partner violence
To assess the degree of regular seasonal fluctuations inintimate partner violence, rates of all types of violent
victimization in which the victim reported that the offender
was a current or ex-spouse, or a current or ex-boyfriend
or girlfriend, were examined. Seasonal rates of intimate
partner violence appeared to peak in the summer in morethan half of the years (figure 12). Statistical analysis of theintimate partner violence rates indicated that there wereseasonal differences between summer rates and the rates
for other seasons (table 3). Compared to the summer,
intimate partner violence was about 12% lower in the winter,
6% lower in the spring, and 9% lower in the fall (table 3).

Table 3
Average percent difference in the seasonal rate of violent
victimization involving intimate partners, weapon use, andinjury, 1993–2010
WinterSpringSummerFall

Intimate partner
violence-11.5%*
-5.8*
~
-9.0*

Serious violence
involving weapons-5.7%*
-4.7*
~
-3.2

Serious violence
resulting in injury-6.7**
-6.7*
~
-5.6

Note: See appendix table 3 for regression coefficients and standard errors.
*Difference is statistically significant (p < .05, two-tail test).
~Highest rate season used for percentage comparisons.
Source: Bureau of Justice Statistics, National Crime Victimization Survey,
1993–2010.

Figure 12
Seasonal rates of intimate partner violence, 1993–2010
Per 1,000 persons age 12 or older
2.0

1.6

1.2

0.8

0.0

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

0.4

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 201414

Serious violence involving weapons
Rates of serious violence involving weapons also exhibitedsome statistically significant patterns of seasonal variation(figure 13). Violence involving weapon use tended to behigher during the summer than during the winter andspring. On average, winter rates of this type of violence
were approximately 6% lower than summer rates, while
spring rates were about 5% lower than summer rates. The
differences between the summer and fall rates were not large
enough across the years to be statistically significant.

Figure 13
Seasonal rates of serious violent crime involving weapons, 1993–2010
Per 1,000 persons age 12 or older
10

8

6

4

0

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

2

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 201415

Serious violence resulting in injury
Seasonal patterns in rates of serious violent victimization
resulting in injury were comparable to those found forserious violence involving weapons (figure 14). Violent
victimizations resulting in serious injury tended to occur at

higher rates during the summer than during the winter andspring. Winter and spring rates of serious violence resulting
in injury were about 7% lower than summer rates. Althoughfall rates were also somewhat lower on average than summer
rates, these differences were not statistically significant.

Figure 14
Seasonal rates of serious violent crime resulting in injury, 1993–2010
Per 1,000 persons age 12 or older
2.0

1.5

1.0

0.0

Winter '93
Summer '93
Winter '94
Summer '94
Winter '95
Summer '95
Winter '96
Summer '96
Winter '97
Summer '97
Winter '98
Summer '98
Winter '99
Summer '99
Winter '00
Summer '00
Winter '01
Summer '01
Winter '02
Summer '02
Winter '03
Summer '03
Winter '04
Summer '04
Winter '05
Summer '05
Winter '06
Summer '06
Winter '07
Summer '07
Winter '08
Summer '08
Winter '09
Summer '09
Winter '10
Summer '10

0.5

Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 201416

Summary
With the exception of robbery, each of the violent andhousehold property crimes exhibited a pattern of recurrent
seasonal fluctuations in their trends from 1993 to 2010.
The most common pattern for household property crimes
was that victimization occurred at higher rates during
the summer than during other seasons. Motor vehicle
theft rates exhibited less regular seasonal fluctuation thanhousehold burglary and larceny. While summer rates ofmotor vehicle theft were higher than spring rates, they
were not significantly different from winter and fall rates.
Across each type of household property victimization, thefluctuations between the seasonal peak and trough rates areless than 11%. In comparison, the variations in the annual
victimization rates from 1993 to 2010 were much larger.
For example, the household property victimization rate
declined 62% from 318.9 per 1,000 households in 1993 to120.2 per 1,000 households in 2010.3 Therefore, the variation
in household victimization rates across the years was larger
than the seasonal fluctuations within the calendar year.
For violent crimes, the most common pattern showed thatvictimization rates were higher during the summer thanduring other seasons of the year. However, this pattern
had two important exceptions. First, unlike any other type
3Criminal Victimization, 2010, NCJ 235508, BJS web, September 2011.

of violence, robbery rates exhibited no regular seasonalvariation over time. Second, simple assault rates were higher
in the fall than in the winter, spring, and summer. Thesefindings indicating little seasonality in robbery and peakrates of simple assault in the fall were similar to those foundin prior BJS research based on victimization data from themid-1970s.4
Intimate partner violence rates were higher during thesummer than during other seasons of the year. This pattern
was more similar to the seasonal variations found for serious
violence than for simple assault victimization. Trends inassault resulting in serious injury and assault involving
weapons also indicated that summer rates were higher than
the rates in other seasons; however, the differences between
fall and summer rates in these types of violence were notstatistically significant. When seasonal differences in various
types of violence were found, the magnitude of the difference
between the peak and trough rates was 12% or less. Like
household property crime, variations in the annual violent
victimization rates from 1993 to 2010 were larger. The
violent victimization rate declined 70% from 49.9 per 1,000
persons age 12 or older in 1993 to 14.9 per 1,000 in 2010,
varying more from 1993 to 2010 than across the seasons of
the year.5
4Crime and Seasonality: National Crime Survey Report, NCJ 64818, BJS web,

May 1980.

5Criminal Victimization, 2010, NCJ 235508, BJS web, September 2011.

Seasonal patterns in Criminal Victimization Trends | June 201417

Methodology
Survey coverage
The National Crime Victimization Survey (NCVS) is anannual data collection conducted by the U.S. Census Bureau
for the Bureau of Justice Statistics (BJS). The NCVS is aself-report survey in which interviewed persons are asked
about the number and characteristics of victimizations they
they experienced during the prior 6 months. The NCVS
collects information on nonfatal personal crimes (rape orsexual assault, robbery, aggravated and simple assault, andpersonal larceny) and household property crimes (burglary,
motor vehicle theft, and other theft) both reported and notreported to police. In addition to providing annual-level andchange estimates on criminal victimization, the NCVS is
the primary source of information on the nature of criminal
victimization incidents. Survey respondents provide
information about themselves (such as age, sex, race andethnicity, marital status, education level, and income) andwhether they experienced a victimization. The survey alsocollects information about the offender in each victimization
incident (such as age, race and ethnicity, sex, and victim–
offender relationship), characteristics of the crime (includingtime and place, use of weapons, nature of injury, andeconomic consequences), whether the crime was reported topolice, reasons why the crime was or was not reported, andexperiences with the criminal justice system.
The NCVS is administered to persons age 12 or older froma nationally representative sample of households in the
United States. The NCVS defines a household as a group of
members who all reside at a sampled address. Persons are
considered household members when the sampled address istheir usual place of residence at the time of the interview andwhen they have no usual place of residence elsewhere. Onceselected, households remain in the sample for 3 years, andeligible persons in these households are interviewed every
6 months for a total of seven interviews. New households
rotate into the sample on an ongoing basis to replaceoutgoing households that have been in the sample for the
3-year period. The sample includes persons living in groupquarters, such as dormitories, rooming houses, and religious
group dwellings, and excludes persons living in military
barracks and institutional settings, such as correctional or
hospital facilities, and homeless shelters. (For more detail,see Survey Methodology in Criminal Victimization in the
United States, 2008, NCJ 231173, BJS web, May 2011.)

Seasonal patterns in Criminal Victimization Trends | June 2014

Nonresponse and weighting adjustments
In 2010, about 41,000 households and 73,300 individuals age
12 or older were interviewed for the NCVS. Each household
was interviewed twice during the year. The response rate
was 92.3% of households and 87.5% of eligible individuals.
Victimizations that occurred outside of the U.S. were
excluded from this report.
Estimates in this report use data from the 1993 to 2010
NCVS data files. These files can be weighted to produce
annual estimates of victimization for persons age 12 or older
living in U.S. households. Because the NCVS relies on asample rather than a census of the entire U.S. population,weights are designed to inflate sample point estimates toknown population totals and to compensate for survey
nonresponse and other aspects of the sample design.
The NCVS data files include both person and household
weights. Person weights provide an estimate of the
population represented by each person in the sample.
Household weights provide an estimate of the U.S.
household population represented by each household in thesample. After proper adjustment, both household and person
weights are also typically used to form the denominator in
calculations of crime rates.
Victimization weights used in this analysis account for
the number of persons present during an incident. Highfrequency repeat victimizations (or series victimizations)
are handled differently in this report than in recent BJS
victimization reports because they present a special problem
for seasonality analysis. Series victimizations are similar in
type but occur with such frequency that a victim is unable
to recall each individual event or describe each event indetail. Survey procedures allow NCVS interviewers to
identify and classify these similar victimizations as series
victimizations and to collect detailed information on only
the most recent incident in the series. Because the monthin which a victimization occurred is recorded only for themost recent incident, series victimizations are treated asa single victimization. The percentage of victimizations
reported as series victimizations declined from 1993 to2010. In 2010, series incidents accounted for about 1%of household property victimizations and about 3% ofviolent victimizations.

18

Methodological changes to the NCVS in 2006
Methodological changes implemented in 2006 may haveaffected the crime estimates for that year to such an extent
that they are not comparable to estimates from other years.
Evaluation of 2007 and later data from the NCVS conducted
by BJS and the Census Bureau found a high degree ofconfidence that estimates for 2007, 2008, 2009, and 2010 are
consistent with and comparable to estimates for 2005 andprevious years. The reports, Criminal Victimization, 2006,
NCJ 219413, December 2007; Criminal Victimization, 2007,
NCJ 224390, December 2008; Criminal Victimization, 2008,
NCJ 227777, September 2009; Criminal Victimization, 2009,
NCJ 231327, October 2010; and Criminal Victimization,
2010, NCJ 235508, September 2011, are available on the
BJS website.
Estimating and analyzing seasonal victimization rates
Victims’ reports of the month in which the incident
occurred are used to estimate seasonal rates of victimization.
Seasons of the year are defined according to the month inwhich the season begins. Therefore, winter rates include in
December, January, and February incidents; spring rates
include March, April, and May incidents; summer rates
include June, July, and August incidents; and fall rates
include September, October, and November incidents. The
1993 to 2010 seasonal victimization rates include incidents
occurring from December 1992 through November 2010.
Seasonal household property victimization rates are
estimated by dividing the weighted number of incidents
by the weighted number of households and multiplying by
1,000. Violent victimization rates are estimated by dividing
the weighted number of incidents by the weighted numberof persons age 12 and older and multiplying by 1,000.
Sampling weights are used in all population estimates.
The NCVS has three important design features that
reduce potential errors in measuring the month in which
victimization occurred. First, the relatively short 6-monthreference period reduces the chances that victims will forget
the incident, underreport victimizations, and attributeincidents to the wrong month. Second, the bounding
procedure provides a reference point for respondents
about previously reported incidents, and thereby reduces
telescoping and minimizes error in assigning dates toincidents. Third, the rotating panel structure of the survey
is designed so that data are collected from respondents ineach month of the year. This minimizes recency bias errors
in reporting the dates of incidents, which may occur if thesurvey was administered only once during a fixed period
each year.

components: the long-term trend, seasonal variation
around that trend, and error. To ensure that the results arerobust, two regression-based approaches were used alongwith various sensitivity tests. For each analysis, variables
representing the seasons of the year were regressed on each
victimization trend to estimate the difference between thepeak seasonal rate and the rates in the other seasons.
The first approach estimated ordinary least squares
regression models for each victimization series and included
year fixed effects to account for the long-term trend.
The degree of autocorrelation in the error structure wasestimated using Breusch-Godfrey tests for up to four lagged
periods. For victimization series in which autocorrelated
error was present, a lagged indicator was found to remove
the autocorrelation. In a few instances, autocorrelated errors
persisted despite a variety of lag specifications; therefore,
Newey-West standard errors were estimated to take into
account the potential influences of autocorrelation andheteroskedasticity in the error structure.
The second approach re-estimated the regression models
for each victimization series using first differences in rates
to examine whether the seasonality results were replicatedwhen the models accounted for possible stochastic
nonstationarity in the trends. Autocorrelated errors weresimilarly assessed and handled in the first-difference models
and the conclusions about the statistical significance of eachof the seasonal coefficients were replicated in these results.
Stationarity in the victimization trends in levels and firstdifferences was examined using Dickey-Fuller and PhilipsPerron tests.
Additional diagnostic tests were performed to ensurethat the models, and therefore estimates of the seasonal
differences, fit the observed seasonal rates. These included
visual inspections of observed and predicted trends andmodel-fit improvement F-tests that compared the results
based on long-term trends to those based on long-term
trends plus seasonal variations. Further details about thisstatistical process using the burglary trend as an illustration
are shown in appendix table 4.
The results from the series of regression models shown inthis report are presented in levels and converted to relative
percentage differences because this information provides amore intuitive interpretation of the magnitude of seasonalvariation relative to the average rate across the time period.
These percentages are obtained by comparing the coefficientfor each season against the estimated comparison rate(typically the summer) represented by the constant. The
regression results that resulted in the percentages are shownin appendix tables 1–4.

The extent and statistical significance of seasonal patterns inhousehold property victimization and violent victimization
are estimated by developing regression models that
decompose each of the victimization trends into three
Seasonal patterns in Criminal Victimization Trends | June 201419

Appendix table 1
Results of regression analyses of seasonal patterns inhousehold property crime victimization, by type of property
crime, 1993–2010
Total property
Crime
Burglary
Winter
-5.91 (0.79)* -1.71 (0.25)*
Spring-6.88 (0.71)* -1.44 (0.23)*
Summer~~Fall-2.69 (0.68)* -0.96 (0.25)*
Constant 85.75 (1.98) 16.31 (0.78)

Motor vehicle
Theft
Larceny-0.11 (0.07)-4.10 (0.64)*-0.28 (0.07)* -5.15 (0.59)*~~
0.00 (0.08)-1.74 (0.59)*
5.00 (0.15)
64.43 (1.49)

Note: All constants are statistically significant (p < .05, two-tail test). Standard
errors are shown in parentheses.
~Comparison season (season with highest average rate).
*Seasonal rate is significantly different from the summer rate (p < .05, two-tailtest).
Source: Bureau of Justice Statistics, National Crime Victimization Survey,
1993–2010.

Appendix table 2
Results of regression analyses of seasonal patterns in violent victimization, by type of crime, 1993–2010
WinterSpringSummerFall
Constant

Total violence-0.62 (0.21)*-0.48 (0.16)*-0.25 (0.20)~
13.98 (0.61)

Serious violence-0.31 (0.09)*-0.26 (0.09)*~-0.18 (0.09)*
5.57 (0.19)

Rape/sexual assault-0.06 (0.03)*-0.04 (.03)~-0.07 (0.03)*
0.67 (0.07)

Robbery-0.04 (0.05)-0.03 (0.05)-0.01 (0.05)~
1.59 (0.08)

Aggravated assault-0.23 (0.06)*-0.20 (0.06)*~-0.12 (0.06)*
3.31 (0.15)

Simple assault-0.48 (0.16)*-0.40 (0.11)*-0.43 (0.15)*~
8.59 (0.45)

Note: All constants are statistically significant (p < .05, two-tail test). Standard errors are shown in parentheses.
~Comparison season (season with highest average rate).
*Seasonal rate is significantly different from the comparison rate (p < .05, two-tail test).
Source: Bureau of Justice Statistics, National Crime Victimization Survey, 1993–2010.

Appendix table 3
Results of regression analyses of seasonal patterns in violent
victimization involving intimate partners, weapon use, andinjury, 1993–2010
WinterSpringSummerFall
Constant

Intimate partner
violence-0.18 (0.05)*-0.09 (0.04)*~-0.14 (0.04)*
1.56 (0.11)

Serious violence
involving weapons-0.23 (0.08)*-0.19 (0.07)*~-0.13 (0.07)
4.04 (0.13)

Serious violence
resulting in injury-0.12 (0.04)*-0.12 (0.04)*~-0.10 (0.05)
1.78 (0.11)

Note: All constants are statistically significant (p < .05, two-tail test). Standard
errors are shown in parentheses.
~Comparison season (season with highest average rate).
*Seasonal rate is significantly different from the summer rate (p < .05, two-tailtest).
Source: Bureau of Justice Statistics, National Crime Victimization Survey,
1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 201420

Appendix table 4
Expanded detail of regression model results for seasonal
burglary rates, 1994–2010
Variable
WinterSpring
Fall
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
Constanta
R2

OLS Model 1
b
s.e.b
-1.33
1.39
-3.16
1.18*
-3.33
1.12*
-4.16
1.06*
-5.69
1.05*
-6.72
1.09*
-7.53
1.06*
-8.00
1.06*
-8.11
1.08*
-7.78
1.11*
-7.81
1.08*
-7.48
1.10*
-7.88
1.10*
-8.66
1.03*
-8.50
1.09*
-9.02
1.20*
-9.18
1.11*
15.28
1.03*
0.91

OLS Model 2
b
s.e.b
-1.71
0.25*
-1.44
0.23*
-0.96
0.25*
-1.33
0.92
-3.16
0.72*
-3.33
0.71*
-4.16
0.71*
-5.69
0.77*
-6.72
0.73*
-7.53
0.79*
-8.00
0.73*
-8.11
0.72*
-7.78
0.70*
-7.81
0.69*
-7.48
0.79*
-7.88
0.71*
-8.66
0.76*
-8.50
0.75*
-9.02
0.74*
-9.18
0.72*
16.31
0.78*
0.96

First differences
model
b
s.e.b
-1.94
0.20*
-1.56
0.17*
-0.84
0.17*
-0.12
0.10
0.61

Note: Breusch-Godfrey test for autocorrelation, not significant (lag 1). DickeyFuller and Phillips-Perron tests show burglary trends are not stationary.
Dickey-Fuller and Phillips-Perron tests show burglary trends are stationary in firstdifferences.
*p < .05 (two-tail test).
aOmitted year is 1993.
Source: Bureau of Justice Statistics, National Crime Victimization Survey,
1993–2010.

Seasonal patterns in Criminal Victimization Trends | June 2014

21

The Bureau of Justice Statistics, located in the Office of Justice Programs,
U.S. Department of Justice, collects, analyzes, and disseminates statisticalinformation on crime, criminal offenders, victims of crime, and the operationof justice systems at all levels of government. William J. Sabol is acting director.
This report was written and verified by Janet L. Lauritsen and Nicole White,
University of Missouri - St. Louis. Lynn Langton assisted with verification.
Jill Thomas edited the report. Barbara Quinn produced the report.
June 2014, NCJ 245959

Office of Justice Programs
Innovation • Partnerships • Safer Neighborhoods
www.ojp.usdoj.gov