U.S. Fire Administration

TOPICAL FIRE RESEARCH SERIES

Volume 2, Issue 6

August 2001 (Rev. March 2002) 

Lightning Fires

FINDINGS

S Each year, lightning is the cause of an estimated 17,400 fires. Injuries

and deaths per lightning fire are relatively small, but dollar loss per fire

is nearly twice that from all U.S. fires.

S Two-thirds of lightning fires occur June–August.

S 55% of lightning fires occur outdoors, and 41% occur in structures.

Deaths and injuries occur mostly in structures (89% and 86%, respectively).

S Roofs, sidewalls, framing, and electrical wires are the areas most

ignited by lightning fires.

Sources: NFPA and NFIRS

Each year, an estimated 17,400 fires are attributed to lightning. Annually, these fires

result in approximately 10 civilian deaths, 75 civilian injuries, and $138 million in property damage.1 (The casualties described are those that result from fires caused by lightning, not those that result from direct lightning strikes.) Casualty losses per lightning fire

are considerably less than those from all U.S. fires, but the dollar loss per fire is nearly

twice as high (Figure 1).

Figure 1. Loss Measures for Lightning Fires

(3-year average, NFIRS data 1996–98)

MEASURE ALL FIRES LIGHTNING FIRES

Dollar Loss/Fire

Injuries/1,000 Fires

Fatalities/1,000 Fires

$5,619

15.7

2.4

$9,262

4.6

0.4

Source: NFIRS only

This topical report presents an overview of some characteristics of these naturally occurring fires.
-

Lightning is a natural phenomenon occurring during electrical storms. It is a discharge of atmospheric electricity and is accompanied by a vivid flash of light, commonly

from one cloud to another, sometimes from a cloud to the earth. Lightning comes from a

parent cumulonimbus cloud (thunderhead). Thunderstorm clouds form wherever there is

enough rapid upward air motion and moisture to produce a deep cloud. These conditions

most often occur in summer—two-thirds of lightning fires occur in June, July, and

August (Figure 2). July has the highest incidence of lightning fire at 25%.

0

5

10

15

20

25

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Percent

Figure 2. Lightning Fires by Month

(3-year average, NFIRS data 1996–98)

Source: NFIRS only

Fifty -five percent of fires caused by lightning strikes occur outside, igniting trees, brush,

grass, or other outside materials (Figure 3). Almost as often (41%), lightning strikes residential and other structures. Lightning strikes rarely cause vehicle fires.

Figure 3. Where Lightning

Fires Occur

LOCATION OF FIRE

Outdoor Fire

Structure Fire

Other Fire

Vehicle Fire

Source: NFIRS only

PERCENT

55

41

3

1
Because most lightning fires occur outdoors, the most prominent form of material

ignited is “growing living form,” which includes trees, brush, and grass (Figure 4). Materials found on residential structures that are commonly ignited include roofs, sidewalls,

and framing. Electrical wiring is another material often ignited, as the electrical current

in lightning is drawn to electrical wires.

Figure 4. Leading Materials Ignited in Lightning Fires

(3-year average, NFIRS data 1996–98)

0 10 0 0 0 0

Growing Living Form

Structural Member, Framing

Exterior Roof Covering

Electrical Wire, Cable Insulation

Exterior Sidewall

AdjustedPercent

Source: NFIRS only

2 3 4 5

Civilians suffer more injuries than fatalities in lightning fires each year. Most casualties result from lightning structure fires rather than outside or other types of lightning

fires. Eighty-nine percent of lightning fire civilian fatalities and 86% of injuries occur in

structure fires. Rarely are civilians injured or killed in outdoor lightning fires (7% of

injuries and 11% of fatalities). Ninety-three percent of all dollar loss from these fires

occur in structure fires.

EXAMPLES

S Residents were evacuated from six homes on June 13, 2001, in Apple Valley,

Minnesota, when lightening struck three gas lines, catching fire. No injuries

resulted.2

S A house fire resulted from a lightening strike on March 4, 2001, in Salt Lake

City, Utah, killing two adults and three children, who were asleep when the lightning

struck their home.3

S In Tallahassee, Florida, on June 4, 2001, firefighters fought a blaze that was

sparked by lightning. The fire burned hundreds of acres in the state.3

CONCLUSION

Lightning fires are a natural phenomenon. Individuals who live in high strike areas

should consult local authorities for current information on how to protect residences and
prevent injuries. For further information on lightning fires, contact the National Oceanic

and Atmospheric Administration (NOAA) or the USFA.

NOTES:

1. National estimates are based on National Fire Incident Reporting System (NFIRS) data (1996–1998)

and the National Fire Protection Association’s (NFPA) annual survey, Fire Loss in the United States.

2. Associated Press, June 13, 2001, Apple Valley Minnesota.

3. The Desert News, March 4, 2001, Salt Lake City, Utah.

4. Associated Press, June 4, 2001, Tallahassee, Florida.

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