Technical Report 2000-01

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National Climatic Data Center

The 2000

Olympic Games–A Climatology For

Sydney,

 Australia 

 

 

US Department of Commerce

NOAA/ NESDIS

National Climatic Data Center

Asheville, NC 28801-5696

August, 2000
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National Climatic Data Center Technical Report No. 2000-01

The 2000 Olympic Games–

A Climatology for Sydney, Australia

 Neal Lott, Tom Ross

August 2000

U.S. Dept of Commerce

National Oceanic and Atmospheric Administration

National Environmental Satellite Data and Information Service

National Climatic Data Center

Asheville, NC 28801-5001

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INTRODUCTION

This report provides climatological summaries for Sydney, Australia, site of this year’s Olympic

Games from September 13 - October 1, 2000. Sydney has a rather mild climate, with usually

favorable weather conditions for athletic events during September–which is early climatological

spring in Australia. The statistics provided in this report are based on a 1939-1991 period of

climatological record. Values presented are in English units, with temperatures in Fahrenheit (F)

and precipitation in inches unless otherwise noted (e.g., C = Celsius, mm = millimeters).

CLIMATOLOGICAL REVIEW

In September, Sydney’s average maximum temperature is 68 degrees F (20 C), with an average

minimum of 50 F (10 C). Temperatures during September have ranged from as high as 95 F (35

C) to as low as 36 F (2 C). However, the maximum temperature reaches or exceeds 80 F (27 C)

only 7% of the time, while the minimum temperature is 45 F (7 C) or higher 84% of the time. So,

extreme temperatures are not common.

Rainfall averages 2.2 inches (56 mm), making September the driest month (on average), with 10

days typically having measurable precipitation. The maximum rainfall observed for the month is

7.4 inches (188 mm), with a minimum of .1 inch (3 mm). The 24-hour maximum is 3.2 inches (81

mm). Thunderstorms are observed on an average of 2 days during the month. 

Obstructions to vision (e.g., rain, drizzle, fog, haze) occur approximately 18% of the time during

September, but this is usually in the form of haze, as fog occurs less than 1% of the time. Dew

points average in the 40's, with humidities in the 50-80% range and an average relative humidity

of 65%. The average wind speed is 7 knots (4 m/sec), with a maximum gust of 60 knots (31

m/sec) for the period of record. The winds exceed 17 knots (9 m/sec) 10% of the time. 

On an annual basis, the average maximum temperature is 72 F (22 C), with an average minimum

of 55 F (13 C), and extremes ranging from a lowest of 32 F (0 C) to a highest of 110 F (43 C). 

Rainfall averages 44.5 inches/year (1130 mm/year), ranging from a minimum of 20.5 inches (521

mm) to a maximum of 79.7 inches (2024 mm).

TABLES/SUMMARIES

The tables which follow are derived from 1939-1991 data provided by the Australian Bureau of

Meteorology. The data were used in production of the International Station Meteorological

Climate Summary CDROM (see http://www.ncdc.noaa.gov/ol/climate/climateproducts.html for

details on this and other CD products), from which these tables were selected. Additional tables

are available on the CD. 
3

The NCDC web site (http://www.ncdc.noaa.gov) has numerous other climatic datasets and

products online, and the Australian Bureau of Meteorology

(http://www.bom.gov.au/olympic/zclimate.htm and

http://www.bom.gov.au/climate/how/newproducts/IDCstoc.shtml) has additional climatic

information for the area.

There are fifteen tables included below, with an overall station climate summary, followed by

several percent frequency tables (e.g., for precipitation, weather, and temperature) and daily

averages and extremes. Where shown, times are always local standard time (LST). Explanations

and examples are provided with each table.

FIGURES

Figures 1 through 6, courtesy of the Australian Bureau of Meteorology, provide a climatic map

overview of Australia and for the Sydney area in particular. These are helpful in gaining a

geographical picture of how Sydney’s climatology relates to its surrounding area and to Australia

as a whole. The average precipitation, maximum temperature, and minimum temperature for

September are presented in the six figures.
4

STA 947670 | ASSY | SYDNEY APT, AU

LAT 33 56S LONG 151 10E ELEV 20(ft) 6(m)

STATION CLIMATIC SUMMARY POR (HOURLY): 1939-1991 

 TEMPERATURE (DEG F)| PRECIPITATION (INCHES) (^) |REL HUM|VAP|DEW| PR |WIND (KTS) | | MEAN NO. OF DAYS WITH (&)

 MEANS |EXTREME| PRECIP. |SNOWFALL |PERCENT|PR |PT.| ALT| |SKY|PRECIP.|SNOW- | | | TEMP (DEG F)

 | | | | | | | |24H| | |24H| (LST) |IN.|(F)| FT.|PREVAIL|MAX|CVR|INCHES |FALL(")|TH |FOG|MAX|MAX|MIN|MIN

 MAX|MIN|AVG|MAX|MIN| MEAN| MAX| MIN|MAX|MEAN|MAX|MAX| AM| PM|HG.| | |DIR|SPD|GST| | >=| >=| >=| >=|STM| * | >=| >=| <=| <=

 | 06| 15| |.01|.50|.10|1.5| | 90| 70| 32| 10

JAN 79 65 72 109 49 4.0 15.8 .2 6.2 **** *** *** 83 62 .54 61 50 NE 12 82 BRK 11 2 0 0 3 1 3 30 0 0

FEB 79 66 73 109 52 4.5 23.3 .3 8.5   ** * *** 85 64 .57 62 50 S 14 58 BRK 12 2 0 0 2 # 2 27 0 0

MAR 77 63 70 106 45 5.2 15.5 .3 7.9   ** * *** 85 61 .53 60 45 S 13 69 BRK 13 3 0 0 2 1 1 29 0 0

APR 73 57 65 96 43 4.2 18.8 .5 6.8   ** * *** 84 59 .44 55 40 S 12 66 SCT 11 2 0 0 1 2 # 22 0 0

MAY 68 51 60 86 37 3.9 16.7 .1 6.5   ** * *** 83 57 .35 49 50 NW 5 70 SCT 12 2 0 0 1 3 0 10 0 0

JUN 63 47 55 80 34 5.2 18.3 .1 5.9   ** * *** 83 58 .30 45 55 W 8 70 BRK 11 3 0 0 1 2 0 2 0 0

JUL 62 44 53 80 32 2.5 10.0 0 5.2   ** * *** 80 52 .27 42 55 NW 6 59 SCT 9 1 0 0 # 1 0 2 # 0

AUG 64 46 55 88 34 3.2 15.3 .2 8.1   ** * *** 79 50 .27 43 55 W 9 62 SCT 10 2 0 0 1 1 0 5 0 0

SEP 68 50 59 95 36 2.2 7.4 .1 3.2   ** * *** 79 52 .31 46 55 NW 7 60 SCT 10 1 0 0 2 2 # 11 0 0

OCT 72 55 64 101 41 3.1 10.7 0 4.4   ** * *** 79 55 .37 51 60 S 13 68 BRK 11 2 0 0 2 1 1 18 0 0

NOV 75 59 67 110 43 3.4 15.6 .2 5.6   ** * *** 78 56 .41 54 60 NE 13 82 BRK 11 2 0 0 4 1 2 22 0 0

DEC 78 63 71 110 47 3.1 14.1 .2 7.2   ** * *** 82 61 .49 58 60 NE 13 68 BRK 11 2 0 0 4 # 3 28 0 0

ANN 72 55 64 110 32 44.5 79.7 20.5 8.5   ** * *** 82 57 .37 51 55 S 10 82 SCT 132 24 0 0 23 15 12 205 # 0

POR 53 53 53 53 53 53 53 53 53 0 0 0 33 34 34 34 34 38 38 53 45 53 53 0 0 53 53 53 53 53 53

F = FAHRENHEIT.

T = TRACE AMOUNTS ( PRECIP < .005", SNOWFALL < .05", OR SNOW DEPTH < .5").

KTS = KNOTS FOR WIND SPEED.

REL HUM = RELATIVE HUMIDITY IN PERCENT.

VAP PR = VAPOR PRESSURE IN INCHES OF MERCURY.

DEW PT = DEW POINT IN DEGREES FAHRENHEIT.

PR ALT = PRESSURE ALTITUDE IN TENS OF FEET (E.G., 50 = 500 FEET).

SKY CVR = THE PREDOMINANT SKY CONDITION, BRK = BROKEN, SCT = SCATTERED CLOUDS.

TH STM = THUNDERSTORM.

TEMP = TEMPERATURE.

# = MEAN NO. DAYS < .5 DAYS.

" = INCHES. 

* = VISIBILITY IS NOT CONSIDERED, MIST INCLUDED WHEN REPORTED.

& = ANN TOTALS MAY NOT EQUAL SUM OF MONTHLY VALUES DUE TO ROUNDING.

^ = 24 HR MAX PRECIP AND SNOWFALL ARE DAILY TOTALS (MID-NIGHT TO MID-NIGHT).

I = MISSING DATA - VALUE NOT COMPUTED.

***... = DATA NOT AVAILABLE.

POR = NUMBER OF YEARS USED FOR THE SUMMARY.

EXAMPLE – THE AVERAGE MAXIMUM TEMPERATURE IN SEPTEMBER IS 68 DEGREES F.
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STATION CLIMATIC SUMMARY (CONTINUED) 

 MEAN NO. OF DAYS WITH (&) | 

 PRECIPITATION | OBSTR TO VISION | 

 |FRZ | |HAIL| |SMOK|BLOW|DUST| OBS| 

 R/DZ|R/DZ|SNOW|/SLT|PRCP|HAZE|SNOW|SAND| VIS|

JAN 16 0 0 # 16 17 0 # 17

FEB 16 0 0 # 16 16 0 # 16

MAR 16 0 0 # 16 17 0 # 18

APR 14 0 0 # 14 15 0 # 16

MAY 14 0 0 0 14 16 0 # 17

JUN 14 0 0 # 14 15 0 0 15

JUL 12 0 0 # 12 16 0 # 16

AUG 13 0 0 # 13 15 0 # 15

SEP 13 0 0 # 13 15 0 # 15

OCT 15 0 0 # 15 16 0 # 16

NOV 16 0 0 # 16 16 0 1 17

DEC 15 0 0 # 15 17 0 1 17

ANN 174 0 0 1 174 191 0 2 195

POR 53 53 53 53 53 53 53 53 53

FRZ = FREEZING.

R/DZ = RAIN OR DRIZZLE.

SLT = SLEET.

PRCP = PRECIPITATION.

OBSTR TO VISION = OBSTRUCTION TO VISION.

SMOK = SMOKE.

BLOW SNOW = BLOWING SNOW.

OBS VIS = OBSTRUCTION TO VISION.

& = ANN TOTALS MAY NOT EQUAL SUM OF MONTHLY VALUES DUE TO ROUNDING.

I = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED.

# = MEAN NO. DAYS < .5 DAYS.

POR = NUMBER OF YEARS USED FOR THE SUMMARY.

EXAMPLE – IN SEPTEMBER, AN AVERAGE OF 13 DAYS HAVE RAIN OR DRIZZLE.
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Percent Frequency Daily PRECIPITATION AMOUNTS

 PERCENT TOTAL TOTAL

 OF DAYS NO. PRECIP

 WITH OF (INCHES)

 INCHES AMOUNTS OBS MEAN HI LOW 

 NONE TRACE .01 <=.05 <=.10 <=.25 <=.50 <=1.0 <=2.5 <=5.0 <=10.0 <=20.0 >20.0 >=.01 

JAN 63.4 0 5.0 7.2 4.1 8.1 4.7 4.3 2.6 .4 .1 0 0 36.6 1608 4.04 15.76 .21

FEB 57.3 0 4.1 9.7 7.1 8.0 5.6 4.1 3.2 .6 .3 0 0 42.7 1456 4.54 23.35 .30

MAR 59.5 0 4.0 9.8 5.0 7.6 5.1 4.7 3.2 .9 .2 0 0 40.5 1612 5.21 15.48 .25

APR 62.2 0 4.5 8.9 4.4 7.5 4.7 3.3 3.9 .6 .1 0 0 37.8 1589 4.24 18.76 .47

MAY 62.7 0 4.0 8.4 5.2 7.1 5.2 4.3 2.7 .5 .1 0 0 37.3 1640 3.90 16.71 .11

JUN 61.6 0 4.7 6.9 3.1 6.6 6.8 5.0 4.5 .8 .1 0 0 38.4 1588 5.16 18.30 .10

JUL 71.0 .1 3.7 7.3 4.3 5.1 3.8 3.2 1.3 .2 .1 0 0 28.9 1642 2.49 9.98 0

AUG 68.1 0 4.5 5.8 5.0 7.1 4.3 2.9 1.8 .5 .1 0 0 31.9 1642 3.20 15.28 .19

SEP 67.6 0 5.2 6.7 6.2 6.6 3.6 2.6 1.2 .3 0 0 0 32.4 1588 2.18 7.45 .06

OCT 64.5 0 5.5 7.9 5.1 7.6 4.0 3.2 1.8 .5 0 0 0 35.5 1641 3.08 10.68 0

NOV 62.0 0 4.5 9.1 4.6 8.6 5.0 4.3 1.4 .3 .2 0 0 38.0 1589 3.36 15.59 .21

DEC 66.1 0 4.1 8.2 4.6 6.8 4.3 4.0 1.8 .1 .1 0 0 33.9 1641 3.06 14.14 .19

ANN 63.9 * 4.5 8.0 4.9 7.2 4.7 3.8 2.4 .5 .1 0 0 36.1 19236 44.47 79.68 20.54

* = PERCENT < .05 

T = ZERO PRECIP, SNOWFALL OR SNOW DEPTH MEASURED BUT A TRACE WAS NOTED

+ = ANNUAL HI AND LOW VALUES ARE DERIVED FROM ANNUAL TOTALS

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED

EXAMPLE – IN SEPTEMBER, 6.7% OF THE DAYS HAVE BETWEEN .02 AND .05 INCHES RAINFALL;

 3.6% OF THE DAYS HAVE BETWEEN .25 AND .50 INCHES RAINFALL.
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Percent Frequency of Hourly Observations of WEATHER CONDITIONS

 SEPTEMBER 

HOURS TSTM RAIN FREEZE SNOW, PERCENT SMOKE BLOWING DUST PERCENT TOTAL 

(LST) &/OR RAIN & SLEET HAIL OBS WITH FOG &/OR SNOW &/OR W/OBST NO. OF

 DRIZZLE FREEZE &/OR PRECIP HAZE SAND VISION OBS. 

 DRIZZLE HAIL

 00 # # # # # # # # # # # #

 03 .1 7.7 0 0 0 7.7 .6 15.9 0 .1 16.6 1379

 06 .4 6.5 0 0 0 6.5 3.4 25.3 0 .3 29.0 1560

 09 .1 7.1 0 0 0 7.1 .5 28.5 0 .3 29.3 1570

 12 .1 6.3 0 0 0 6.3 .1 16.3 0 .2 16.6 1570

 15 .4 6.8 0 0 0 6.8 0 11.8 0 .4 12.2 1569

 18 .5 8.1 0 0 0 8.1 0 14.1 0 .3 14.4 1491

 21 .2 7.8 0 0 0 7.8 0 8.5 0 .3 8.8 1493

 ALL .2 7.2 0 0 0 7.2 .7 17.3 0 .3 18.2 10632

TSTM = THUNDERSTORM.

OBS = OBSERVATIONS.

OBST VISION = OBSTRUCTIONS TO VISION.

* = PERCENT < .05 

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED.

EXAMPLE – AT 12 NOON LOCAL TIME IN SEPTEMBER, THUNDERSTORMS OCCUR AN AVERAGE OF .1% OF THE TIME;

 RAIN OR DRIZZLE OCCURS AN AVERAGE OF 6.3% OF THE TIME.
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ATMOSPHERIC PHENOMENON – PERCENT OF DAYS WITH EACH TYPE OF WEATHER SOMETIME DURING THE DAY

MONTH HOURS TSTM RAIN FREEZE SNOW, PERCENT SMOKE BLOWING DUST PERCENT TOTAL 

 (LST) &/OR RAIN & SLEET, HAIL OBS WITH FOG &/OR SNOW &/OR W/OBST NO.OF

 DRIZZLE FREEZE &/OR PRECIP HAZE SAND VISION OBS. 

 DRIZZLE HAIL

 JAN DAILY 9.3 51.4 0 0 .2 51.4 1.7 54.0 0 1.2 55.2 1610

 FEB DAILY 8.8 56.2 0 0 .1 56.2 1.5 56.0 0 .7 56.7 1456

 MAR DAILY 5.3 52.9 0 0 .2 53.0 4.2 55.7 0 .4 56.9 1612

 APR DAILY 3.9 47.4 0 0 .3 47.5 7.1 50.9 0 .2 53.0 1590

 MAY DAILY 2.7 46.7 0 0 0 46.7 8.6 52.8 0 .4 54.7 1641

 JUN DAILY 2.4 47.5 0 0 .1 47.5 6.1 49.1 0 0 50.2 1589

 JUL DAILY 1.6 38.6 0 0 .1 38.6 4.6 50.3 0 .3 51.4 1643

 AUG DAILY 3.5 42.8 0 0 .5 42.9 3.3 48.0 0 .2 48.6 1643

 SEP DAILY 5.1 44.3 0 0 .4 44.5 5.2 49.1 0 1.2 50.7 1588

 OCT DAILY 7.2 48.7 0 0 .1 48.7 3.0 50.7 0 1.5 51.4 1642

 NOV DAILY 11.7 52.0 0 0 .5 52.2 2.2 54.9 0 2.0 55.7 1589

 DEC DAILY 11.4 49.0 0 0 .7 49.1 1.5 53.6 0 2.1 55.1 1643

 ANN DAILY 6.0 48.0 0 0 .3 48.1 4.1 52.1 0 .8 53.3 19246

TSTM = THUNDERSTORM.

OBS = OBSERVATIONS.

OBST VISION = OBSTRUCTIONS TO VISION.

* = PERCENT < .05

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED

EXAMPLE – IN SEPTEMBER, 44.3% OF THE DAYS HAVE RAIN OR DRIZZLE SOMETIME DURING THE DAY (INCLUDES

 DRIZZLE WITH NO MEASURABLE RAIN).
9

Percent Frequency of Hourly WIND DIRECTION vs WEATHER CONDITIONS

 SEPTEMBER 

WIND RAIN RAIN FREEZE SLEET SNOW HAIL THUNDER FOG ICE FOG SMOKE BLOWING BLOWING NO

DIR. SHOWRS DRIZZLE RAIN " SHOWRS " GRAINS SMALL TORNADO GROUND HAZE SNOW SAND WEATHER 

 FREEZE ICE " PELLET HAIL SQUALLS FOG DUST 

 N 5.9 .2 .2 0 0 0 0 .5 0 0 7.1 0 .2 67.5

 NNE 5.1 0 0 0 0 0 0 .2 .2 0 7.3 0 .2 64.3

 NE 3.2 .5 .5 0 0 0 0 .4 0 0 6.0 0 0 67.2

 ENE 4.0 .7 0 0 0 0 0 .4 0 0 1.8 0 0 79.4

 E 3.7 4.4 .7 0 0 0 0 .3 0 0 1.3 0 0 80.8

 ESE 4.7 3.5 .6 0 0 0 0 0 0 0 1.2 0 0 84.3

 SE 4.1 4.1 1.3 0 0 0 0 0 0 0 1.3 0 0 83.8

 SSE 4.5 2.7 1.1 0 0 0 0 .2 0 0 1.3 0 0 84.8

 S 6.7 7.7 .9 0 0 0 0 .4 0 0 1.1 0 .2 76.4

 SSW 11.4 10.1 1.0 0 0 0 0 0 0 0 .2 0 0 74.2

 SW 9.9 6.4 .7 0 0 0 0 .2 0 0 1.5 0 0 77.8

 WSW 3.5 2.9 .2 0 0 0 0 .4 0 0 .8 0 .4 90.2

 W 1.7 1.1 .4 0 0 0 0 0 .3 .1 2.9 0 0 89.1

 WNW 2.1 .6 .2 0 0 0 0 .4 .7 0 7.4 0 .1 78.7

 NW 2.7 .5 .2 0 0 0 0 .2 1.7 .2 15.2 0 .4 63.5

 NNW 3.3 .9 0 0 0 0 0 .4 .7 0 12.0 0 .2 67.9

 VAR 0 0 0 0 0 0 0 0 0 0 0 0 0 0

 CLM 3.5 .9 .7 0 0 0 0 .1 1.6 .5 12.1 0 .1 63.0

%TOTAL 4.2 2.4 .5 0 0 0 0 .2 .5 .1 6.1 0 .1 74.4

* = PERCENT < .05 

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED.

CLM = CALM.

EXAMPLE – IN SEPTEMBER, WHEN WINDS ARE FROM THE S (SOUTH), RAIN OCCURS 6.7% OF THE TIME,

 WHILE NO SIGNIFICANT WEATHER OCCURS 76.4% OF THE TIME.
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Cumulative Percent Frequency Daily MAXIMUM TEMPERATURES 

Temp(F) JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN

 >=110 0 0 0 0 0 0 0 0 0 0 .1 .1 *

 >=105 1.1 .3 .1 0 0 0 0 0 0 0 .3 .6 .2

 >=100 2.0 1.4 .4 0 0 0 0 0 0 .2 1.1 1.8 .6

 >=95 4.1 3.3 1.2 .1 0 0 0 0 .1 1.1 3.1 4.6 1.5

 >=90 8.4 7.4 4.0 .5 0 0 0 0 .5 3.6 6.2 9.9 3.4

 >=85 17.7 15.5 10.7 3.9 .1 0 0 .2 2.6 8.1 12.1 18.2 7.4

 >=80 41.0 42.9 31.0 12.1 1.9 .1 .1 .8 7.3 17.1 23.7 35.3 17.6

 >=75 72.3 76.0 65.2 36.5 8.8 .4 .7 4.3 16.7 32.0 43.1 63.9 34.6

 >=70 96.1 97.0 93.0 72.8 33.4 6.2 5.9 15.3 37.2 57.5 74.8 88.9 56.1

 >=65 99.9 99.9 99.8 95.4 75.6 34.8 27.2 45.7 67.7 84.2 95.8 99.3 76.8

 >=60 100 100 100 99.9 97.2 84.8 75.2 84.1 94.2 98.5 99.9 100 94.4

 >=55 100 100 100 100 100 99.5 98.5 99.5 100 100 100 100 99.8

 >=50 100 100 100 100 100 100 99.9 99.9 100 100 100 100 100

 >=45 100 100 100 100 100 100 100 100 100 100 100 100 100

 MEAN 79.1 79.1 77.3 73.1 67.8 63.3 62.3 64.4 68.3 72.1 75.1 78.1 71.6

 STDV 7.2 6.6 5.9 5.6 4.7 3.8 4.1 5.1 6.7 7.8 7.9 7.9 8.7

 #OBS 1608 1456 1611 1589 1640 1588 1642 1637 1588 1641 1588 164119229

* = PERCENT < .05 

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED.

STDV = STANDARD DEVIATION.

#OBS = NUMBER OF OBSERVATIONS.

EXAMPLE – IN SEPTEMBER, THE DAILY MAXIMUM TEMPERATURE REACHES 80 DEGREES F

 OR HIGHER 7.3% OF THE TIME (I.E., AN AVERAGE OF 7.3% OF THE DAYS). 
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Cumulative Percent Frequency Daily MINIMUM TEMPERATURES

Temp(F) JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN

 >=75 .2 .6 0 0 0 0 0 0 0 .1 0 .2 .1

 >=70 13.2 15.9 5.2 .1 0 0 0 0 .1 .2 .1 4.3 3.2

 >=65 59.9 63.7 39.2 7.0 .2 0 0 .2 .6 3.0 12.5 38.3 18.4

 >=60 91.2 93.9 78.5 34.6 6.2 .7 .1 .4 3.5 21.1 49.4 78.4 37.7

 >=55 98.9 99.7 96.2 68.0 25.0 8.8 2.4 5.0 17.2 53.5 80.9 96.8 53.9

 >=50 99.9 100 99.6 90.7 56.8 29.3 12.9 21.1 49.5 84.3 96.7 99.9 69.7

 >=45 100 100 100 99.4 88.0 63.3 40.9 57.2 83.8 98.8 99.9 100 85.7

 >=40 100 100 100 100 99.6 93.7 82.4 92.4 99.2 100 100 100 97.2

 >=35 100 100 100 100 100 99.9 99.4 99.9 100 100 100 100 99.9

 >=30 100 100 100 100 100 100 100 100 100 100 100 100 100

 MEAN 65.2 65.7 62.9 56.9 50.9 46.8 43.9 45.8 49.7 55.0 59.0 62.9 55.3

 STDV 4.0 3.8 4.4 5.2 5.2 5.1 4.7 4.8 5.0 5.1 4.7 4.3 8.9

 #OBS 1608 1454 1611 1588 1640 1588 1639 1638 1569 1622 1589 163819184

* = PERCENT < .05 

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED.

STDV = STANDARD DEVIATION.

#OBS = NUMBER OF OBSERVATIONS.

EXAMPLE – IN SEPTEMBER, THE DAILY MINIMUM TEMPERATURE IS 50 DEGREES F OR

 HIGHER 49.5% OF THE TIME (I.E., 49.5% OF THE DAYS).
12

Daily Average and Extreme Temperatures by Day of Year

 SEPTEMBER 

 | MEAN TEMP | MAXIMUM TEMPERATURE | MINIMUM TEMPERATURE |

 | | AVERAGE | EXTREME | AVERAGE | EXTREME |

DAY | DEG F DEG C| DEG F DEG C| DEG F DEG C DATE| DEG F DEG C| DEG F DEG C DATE|

 1 56.7 13.7 66.0 18.9 76.0 24.4 1969. 47.3 8.5 36.0 2.2 1967.

 2 57.3 14.1 67.0 19.4 87.0 30.6 1982. 47.7 8.7 38.0 3.3 1945.

 3 57.9 14.4 66.9 19.4 79.0 26.1 1982. 48.9 9.4 41.0 5.0 1963.+

 4 56.9 13.8 66.4 19.1 80.0 26.7 1962. 47.3 8.5 41.0 5.0 1957.+

 5 57.2 14.0 66.5 19.2 83.0 28.3 1986.+ 47.9 8.8 40.0 4.4 1940.

 6 57.7 14.3 67.9 19.9 82.0 27.8 1972.+ 47.4 8.6 40.0 4.4 1960.+

 7 57.8 14.4 67.5 19.7 85.0 29.4 1972. 48.2 9.0 39.0 3.9 1955.

 8 58.5 14.7 69.3 20.7 89.0 31.7 1953. 47.6 8.7 38.0 3.3 1946.

 9 58.8 14.9 68.1 20.1 85.0 29.4 1981. 49.5 9.7 40.0 4.4 1962.

 10 58.0 14.5 67.2 19.6 85.0 29.4 1989. 48.8 9.3 40.0 4.4 1947.

 11 59.3 15.1 68.3 20.2 89.0 31.7 1981. 50.2 10.1 42.0 5.6 1952.

 12 58.6 14.8 68.2 20.1 92.0 33.3 1946. 49.0 9.5 40.0 4.4 1970.+

 13 58.0 14.4 67.0 19.4 88.0 31.1 1946. 49.0 9.5 38.0 3.3 1969.+

 14 58.4 14.7 67.5 19.7 83.0 28.3 1947. 49.3 9.6 41.0 5.0 1962.

 15 59.0 15.0 68.7 20.4 87.0 30.6 1942. 49.2 9.6 41.0 5.0 1943.

 16 58.7 14.9 67.9 19.9 82.0 27.8 1963. 49.6 9.8 44.0 6.7 1977.+

 17 59.3 15.2 68.6 20.3 87.0 30.6 1979.+ 49.9 10.0 39.0 3.9 1944.

 18 59.0 15.0 68.3 20.2 86.0 30.0 1951. 49.6 9.8 39.0 3.9 1943.

 19 59.7 15.4 68.8 20.4 86.0 30.0 1951. 50.6 10.3 42.0 5.6 1972.+

 20 59.1 15.1 68.6 20.3 84.0 28.9 1971. 49.7 9.8 40.0 4.4 1969.

 21 59.5 15.3 68.7 20.4 90.0 32.2 1941. 50.3 10.2 36.0 2.2 1943.

 22 60.6 15.9 70.1 21.2 90.0 32.2 1952. 51.1 10.6 42.0 5.6 1963.

 23 59.7 15.4 68.8 20.4 89.0 31.7 1983. 50.7 10.4 42.0 5.6 1962.

 24 59.5 15.3 68.1 20.1 85.0 29.4 1988. 51.0 10.6 41.0 5.0 1946.

 25 60.0 15.5 69.1 20.6 94.0 34.4 1980. 50.8 10.4 41.0 5.0 1969.

 26 59.7 15.4 68.2 20.1 95.0 35.0 1965. 51.2 10.7 43.0 6.1 1974.+

 27 60.3 15.7 69.3 20.7 89.0 31.7 1987. 51.3 10.7 42.0 5.6 1968.+

 28 61.1 16.2 70.3 21.3 91.0 32.8 1987. 52.0 11.1 43.0 6.1 1968.+

 29 61.7 16.5 71.3 21.8 86.0 30.0 1987. 52.2 11.2 45.0 7.2 1948.

 30 61.6 16.4 70.1 21.2 93.0 33.9 1980. 53.1 11.7 43.0 6.1 1982.+

MONTH 59.0 15.0 68.3 20.2 95.0 35.0 1965. 49.7 9.8 36.0 2.2 1967.+

T = TRACE AMOUNTS (<.01 OR <.5 OR < 1.0 INCHES). 

+ = SAME AMOUNT OCCURRED IN PREVIOUS YEAR(S) (EXCEPT FOR 0.0).

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED.

EXAMPLE – THE DAILY MEAN TEMPERATURE ON SEPTEMBER 20 IS 59.1 DEGREES F.
13

Hourly DRY-BULB TEMPERATURE (F) Means and Standard Deviations

HOURS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL

(LST) 

 -MEAN 0 0 0 0 0 0 0 0 0 0 0 0 0

 00-STDV 0 0 0 0 0 0 0 0 0 0 0 0 0

 -#OBS # # # # # # # # # # # # #

 

 -MEAN 67.0 68.0 65.8 60.3 54.2 50.3 47.8 49.5 53.3 58.0 61.3 64.7 57.1

 03-STDV 4.0 3.6 4.1 5.1 5.3 5.4 5.1 5.1 5.2 5.3 4.7 4.2 8.3

 -#OBS 835 762 1288 1376 1423 1380 1425 1424 1379 1367 810 835 14304

 -MEAN 66.4 66.8 64.4 58.7 52.9 49.1 46.3 48.0 51.6 56.8 61.1 64.5 55.8

 06-STDV 4.0 3.9 4.6 5.5 5.6 5.7 5.4 5.3 5.6 5.6 5.0 4.2 8.7

 -#OBS 941 849 1410 1557 1619 1581 1636 1631 1559 1459 905 907 16054

 -MEAN 72.2 72.3 70.1 64.4 57.6 52.7 50.6 53.9 59.5 64.8 68.4 70.8 61.8

 09-STDV 4.9 4.4 4.0 4.5 4.6 4.7 4.5 4.4 4.9 5.5 6.0 5.5 8.9

 -#OBS 1007 910 1455 1572 1618 1566 1625 1628 1570 1505 942 981 16379

 -MEAN 75.5 75.7 74.6 70.4 64.9 60.3 59.0 61.4 65.4 69.2 72.0 74.1 67.5

 12-STDV 6.9 6.0 5.7 5.3 4.4 3.7 3.8 4.7 6.3 7.5 7.6 7.2 8.1

 -#OBS 948 863 1413 1566 1621 1576 1636 1634 1570 1479 910 912 16128

 -MEAN 75.2 75.7 74.7 70.9 66.0 61.7 60.7 62.5 65.7 68.9 71.2 73.4 68.0

 15-STDV 6.6 5.7 5.5 5.5 4.7 4.0 4.2 5.2 6.5 7.3 7.5 7.0 7.7

 -#OBS 1011 923 1458 1570 1628 1580 1636 1631 1569 1512 941 976 16435

 -MEAN 72.6 72.9 71.7 67.3 62.0 57.7 56.4 58.3 61.8 65.3 68.1 70.9 64.4

 18-STDV 5.4 4.2 4.1 4.4 4.2 3.4 3.6 4.2 5.4 5.9 5.9 5.7 7.3

 -#OBS 897 814 1355 1495 1545 1493 1543 1543 1491 1398 835 890 15299

 -MEAN 70.3 70.9 69.7 65.0 58.9 54.5 52.7 55.2 59.1 62.8 65.4 68.4 61.6

 21-STDV 4.3 3.5 3.6 4.4 4.7 4.2 4.2 4.4 4.9 4.9 4.7 4.6 7.6

 -#OBS 897 819 1329 1464 1518 1467 1516 1546 1493 1397 840 892 15178

 -MEAN 71.4 71.9 70.2 65.4 59.6 55.3 53.4 55.6 59.6 63.8 66.9 69.7 62.4

 ALL-STDV 6.3 5.6 5.9 6.6 6.7 6.4 6.8 7.0 7.5 7.6 7.3 6.6 9.2

 -#OBS 6536 5940 9708 10600 10972 10643 11017 11037 10631 10117 6183 6393 109777

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED.

STDV = STANDARD DEVIATION.

#OBS = NUMBER OF OBSERVATIONS.

EXAMPLE – IN SEPTEMBER, THE TEMPERATURE AVERAGES 65.7 DEGREES F AT 1500 (3 PM) LOCAL 

 STANDARD TIME, WITH A STANDARD DEVIATION OF 6.5 DEGREES F.
14

Percent Frequency TEMPERATURE vs WIND DIRECTION (from HOURLY DATA)

 SEPTEMBER 

 WIND DIRECTION

 TEMP. NNW NNE ENE ESE SSE SSW WSW WNW CALM TOTAL PERCENT

(Deg F) & N &NE & E &SE & S &SW & W &NW FREQ. TOTAL 

 >=92 0 0 0 0 0 0 0 100 0 3 *

 >=87 0 5.3 5.3 0 0 0 26.3 57.9 5.3 19 .2

 >=82 26.6 4.7 1.6 0 0 0 20.3 43.8 3.1 64 .6

 >=77 27.7 15.0 4.0 .6 .6 0 12.1 38.2 1.7 173 1.6

 >=72 20.4 21.3 6.1 1.1 1.4 2.3 13.8 30.6 2.9 441 4.1

 >=67 14.1 27.9 9.2 3.8 3.5 2.8 15.6 19.9 3.2 1016 9.5

 >=62 8.8 23.4 9.0 9.8 15.4 3.7 11.9 11.3 6.6 2324 21.8

 >=57 5.2 7.1 6.4 9.3 27.0 9.9 11.7 10.8 12.6 3080 28.9

 >=52 4.3 1.5 1.6 3.7 13.8 15.1 17.9 17.3 24.6 2030 19.1

 >=47 6.5 .3 .1 .2 1.3 7.2 22.7 29.1 32.7 1062 10.0

 >=42 8.9 0 0 0 0 1.6 18.8 45.3 25.4 426 4.0

 >=37 0 0 0 0 0 0 23.1 69.2 7.7 13 .1

TOTALS 8.0 11.3 5.3 6.0 14.3 7.7 14.9 17.9 14.6 10651 100

* = PERCENT < .05 

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED.

EXAMPLE – IN SEPTEMBER, WHEN THE TEMPERATURE IS 87 DEGREES F OR HIGHER, THE WINDS

 ARE FROM THE WNW-NW 57.9% OF THE TIME.
15

Hourly DEW POINT TEMPERATURE (F) Means and Standard Deviations

HOURS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

(LST) 

 -MEAN 0 0 0 0 0 0 0 0 0 0 0 0 0

 00-STDV 0 0 0 0 0 0 0 0 0 0 0 0 0

 -#OBS # # # # # # # # # # # # #

 

 -MEAN 61.2 62.6 60.5 54.9 48.6 44.4 41.0 42.2 46.0 50.7 54.0 58.8 50.6

 03-STDV 5.7 5.4 5.7 6.7 7.0 6.5 5.9 6.4 6.5 6.9 7.6 6.1 9.6

 -#OBS 682 621 1102 1197 1240 1200 1271 1270 1259 1184 630 651 12307

 -MEAN 61.0 62.1 59.7 54.1 47.8 43.8 40.2 41.5 45.0 50.0 53.7 58.6 49.9

 06-STDV 5.5 5.3 5.9 6.7 7.0 6.6 5.9 6.4 6.4 7.1 7.8 6.2 9.7

 -#OBS 682 622 1103 1197 1240 1200 1270 1270 1259 1184 630 651 12308

 -MEAN 60.7 62.3 60.6 55.2 49.2 44.9 41.5 42.6 46.0 50.3 52.9 57.7 50.6

 09-STDV 6.3 5.7 6.4 6.9 7.1 6.5 6.0 6.8 7.0 7.7 8.6 7.4 9.7

 -#OBS 682 621 1103 1196 1238 1200 1271 1271 1260 1184 630 651 12307

 -MEAN 60.5 61.9 59.9 55.0 49.7 45.7 42.2 42.4 45.4 49.6 52.6 57.8 50.6

 12-STDV 6.5 5.8 6.6 7.2 7.6 7.0 6.9 7.3 7.7 8.6 9.2 7.3 9.9

 -#OBS 682 622 1100 1196 1239 1200 1271 1270 1259 1183 630 651 12303

 -MEAN 60.8 62.0 59.9 55.1 49.4 45.5 41.7 42.1 45.7 50.0 53.0 57.8 50.5

 15-STDV 6.1 5.7 6.8 7.5 8.1 7.6 7.5 8.1 8.0 8.6 9.3 7.5 10.2

 -#OBS 682 622 1102 1197 1239 1200 1271 1270 1260 1184 630 650 12307

 -MEAN 61.4 62.6 60.9 56.2 50.7 46.7 43.3 44.0 47.3 51.4 54.1 58.5 51.8

 18-STDV 5.9 5.5 6.1 6.9 7.4 7.0 6.7 7.5 7.5 8.0 8.7 7.0 9.6

 -#OBS 682 621 1102 1195 1239 1200 1270 1270 1260 1184 630 651 12304

 -MEAN 62.0 63.4 61.4 56.5 50.4 46.2 42.9 44.0 47.9 52.1 54.9 59.4 52.1

 21-STDV 5.6 5.4 5.7 6.7 7.3 6.7 6.5 6.9 6.9 7.3 7.9 6.3 9.5

 -#OBS 682 622 1102 1197 1240 1200 1270 1269 1257 1183 630 651 12303

 -MEAN 61.1 62.4 60.4 55.3 49.4 45.3 41.8 42.7 46.2 50.6 53.6 58.4 50.9

 ALL-STDV 6.0 5.6 6.2 7.0 7.4 6.9 6.6 7.1 7.2 7.8 8.5 6.9 9.8

 -#OBS 4774 4351 7714 8375 8675 8400 8894 8890 8814 8286 4410 4556 86139

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED.

STDV = STANDARD DEVIATION.

#OBS = NUMBER OF OBSERVATIONS.

EXAMPLE – IN SEPTEMBER, THE DEW POINT AVERAGES 45.7 DEGREES F AT 1500 (3 PM) LOCAL 

 STANDARD TIME, WITH A STANDARD DEVIATION OF 8.0 DEGREES F.
16

Cumulative Percent Frequency of Hourly RELATIVE HUMIDITY (IN %)

 SEPTEMBER 

HOURS PERCENTAGE FREQUENCY OF RELATIVE HUMIDITY GREATER THAN MEAN TOTAL

(LST) 10% 20% 30% 40% 50% 60% 70% 80% 90% RELATIVE NO. OF

 HUMIDITY OBS.

 00 # # # # # # # # # # #

 03 100 99.9 99.9 98.6 94.9 86.2 71.3 50.4 19.3 77.9 1253

 06 100 100 100 98.6 95.6 88.4 75.6 53.3 23.7 79.4 1251

 09 100 99.9 98.6 90.3 77.1 56.7 34.2 15.1 3.1 63.1 1260

 12 99.9 98.1 88.6 70.2 49.4 28.6 13.4 7.9 1.4 51.4 1259

 15 99.8 96.8 85.8 72.2 55.4 31.3 14.0 6.8 1.0 51.8 1259

 18 99.9 99.0 94.9 85.9 76.3 57.8 30.2 12.6 1.8 61.5 1260

 21 100 99.8 98.6 95.2 85.8 72.0 47.5 24.0 3.4 68.2 1256

 ALL 100 99.1 95.2 87.3 76.3 60.1 40.8 24.3 7.7 64.8 8798

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED.

EXAMPLE – IN SEPTEMBER AT 12 NOON LOCAL TIME, THE RELATIVE HUMIDITY EXCEEDS 60% ONLY 28.6% 

 OF THE TIME.
17

Frequency Surface WIND DIRECTION vs SPEED (from HOURLY DATA) 

SEPTEMBER LST

 | SPEED (KNOTS) | TOTAL|MEAN 

16 PT.| 1 - 3| 4 - 6| 7-10| 11-16| 17-21| 22-27| 28-33| 34-40| 41-47| 48-55| >=56|PERCNT|WIND 

 DIR. | | | | | | | | | | | | |SPEED 

 N .8 .9 1.0 .9 .2 * 0 0 0 0 0 3.8 7.8

 NNE .4 .8 1.4 1.4 .3 * 0 0 0 0 0 4.3 9.8

 NE .5 1.0 2.3 2.5 .6 .1 * 0 0 0 0 7.0 10.4

 ENE .6 .6 .8 .5 * 0 0 0 0 0 0 2.5 7.2

 E .8 1.0 .7 .3 * * 0 0 0 0 0 2.8 5.9

 ESE .4 .7 .4 .1 0 0 0 0 0 0 0 1.6 5.7

 SE .5 1.3 1.6 .8 .1 0 * 0 0 0 0 4.4 8.1

 SSE .5 .9 1.7 1.7 .3 .1 * 0 0 0 0 5.2 10.0

 S .6 .9 2.0 3.4 1.5 .7 .1 0 0 0 0 9.2 12.7

 SSW .4 .5 .7 1.3 .6 .5 * * 0 0 0 3.9 12.7

 SW .7 .8 .8 1.0 .4 .1 * 0 0 0 0 3.8 9.4

 WSW .6 1.0 1.2 1.3 .5 .2 * * 0 0 0 4.8 10.1

 W 1.8 2.2 2.6 2.1 .9 .5 .1 * * 0 0 10.1 9.5

 WNW 2.3 1.8 1.4 1.0 .5 .4 .1 0 0 0 0 7.6 8.0

 NW 3.9 2.8 1.8 1.1 .6 .2 * 0 0 0 0 10.3 6.5

 NNW 1.1 1.2 .8 .8 .2 .1 * 0 0 0 0 4.2 7.8

 VAR 0 0 0 0 0 0 0 0 0 0 0 0 0

 CLM 0 0 0 0 0 0 0 0 0 0 0 14.6 0

 ALL 15.8 18.5 21.0 20.2 6.6 2.8 .5 .1 * 0 0 100 7.8

* = PERCENT < .05 

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED.

CLM = CALM.

EXAMPLE – IN SEPTEMBER, THE WIND SPEED IS IN A RANGE OF 11-16 KNOTS 20.2% OF THE TIME OVERALL,

 WITH 11-16 KNOTS FROM THE SOUTH OCCURRING 3.4% OF THE TIME.
18

Hourly SEA LEVEL PRESSURE (MB) Means and Standard Deviations

HOURS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

(LST) 

 -MEAN 0 0 0 0 0 0 0 0 0 0 0 0 0

 00-STDV 0 0 0 0 0 0 0 0 0 0 0 0 0

 -#OBS # # # # # # # # # # # # #

 

 -MEAN 1013.5 1013.8 1016.3 1018.4 1018.9 1019.3 1018.9 1017.6 1017.1 1015.3 1012.9 1012.1 1016.8

 03-STDV 5.5 5.5 5.5 5.9 7.0 7.8 7.4 7.3 7.3 6.8 6.2 5.8 7.1

 -#OBS 651 593 1102 1197 1240 1200 1271 1270 1230 1184 630 651 12219

 -MEAN 1014.3 1014.3 1016.8 1018.8 1019.1 1019.4 1019.0 1017.9 1017.6 1016.0 1013.6 1012.9 1017.2

 06-STDV 5.6 5.5 5.5 5.9 7.1 7.9 7.4 7.4 7.3 6.8 6.2 5.8 7.1

 -#OBS 651 594 1103 1197 1240 1200 1270 1270 1229 1184 630 651 12219

 -MEAN 1014.9 1015.3 1017.9 1020.0 1020.2 1020.5 1020.1 1018.9 1018.6 1016.7 1014.1 1013.4 1018.2

 09-STDV 5.7 5.5 5.6 6.0 7.2 8.0 7.5 7.6 7.5 7.1 6.5 5.9 7.2

 -#OBS 651 593 1103 1196 1238 1200 1271 1271 1230 1183 630 651 12217

 -MEAN 1014.3 1014.7 1017.1 1019.0 1019.1 1019.6 1019.1 1017.8 1017.4 1015.4 1013.0 1012.4 1017.2

 12-STDV 5.9 5.6 5.7 6.2 7.3 7.9 7.6 7.6 7.5 7.2 6.5 6.1 7.3

 -#OBS 651 594 1101 1196 1239 1200 1271 1270 1230 1183 630 651 12216

 -MEAN 1013.1 1013.4 1015.6 1017.5 1017.8 1018.2 1017.7 1016.2 1015.8 1013.9 1011.8 1011.2 1015.7

 15-STDV 6.0 5.6 5.8 6.2 7.3 7.8 7.5 7.5 7.5 7.1 6.4 6.2 7.3

 -#OBS 651 594 1102 1197 1239 1200 1271 1270 1230 1184 630 650 12218

 -MEAN 1013.0 1013.5 1015.9 1018.0 1018.5 1019.0 1018.4 1017.0 1016.5 1014.7 1012.3 1011.4 1016.3

 18-STDV 5.9 5.5 5.7 6.1 7.1 7.7 7.3 7.3 7.3 6.9 6.3 6.1 7.2

 -#OBS 651 593 1102 1197 1239 1200 1270 1270 1230 1184 630 651 12217

 -MEAN 1014.6 1015.1 1017.4 1019.3 1019.6 1019.9 1019.4 1018.2 1017.9 1016.3 1014.1 1013.0 1017.6

 21-STDV 5.8 5.4 5.6 6.0 7.0 7.7 7.2 7.2 7.1 6.8 6.2 5.9 7.0

 -#OBS 651 594 1102 1197 1240 1200 1271 1269 1228 1183 630 651 12216

 -MEAN 1014.0 1014.3 1016.7 1018.7 1019.0 1019.4 1018.9 1017.7 1017.3 1015.5 1013.1 1012.4 1017.0

 ALL-STDV 5.8 5.5 5.7 6.1 7.2 7.9 7.5 7.5 7.4 7.0 6.4 6.0 7.2

 -#OBS 4557 4155 7715 8377 8675 8400 8895 8890 8607 8285 4410 4556 85522

# = EXCESSIVE MISSING DATA - VALUE NOT COMPUTED

STDV = STANDARD DEVIATION.

#OBS = NUMBER OF OBSERVATIONS.

EXAMPLE – IN SEPTEMBER, THE MEAN SEA LEVEL PRESSURE IS 1017.3 MILLIBARS, FOR ALL HOURS COMBINED.
19

Figure 1

Figure 2
20

Figure 3

Figure 4
21

Figure 5

Figure 6