Climatological Report (Monthly)
Issued by NWS Sterling, VA

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000 CXUS51 KLWX 011451 CLMIAD CLIMATE REPORT NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1051 AM EDT FRI OCT 01 2021 ................................... ...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2021... CLIMATE NORMAL PERIOD: 1991 TO 2020 CLIMATE RECORD PERIOD: 1960 TO 2021 WEATHER OBSERVED NORMAL DEPART LAST YEAR`S VALUE DATE(S) VALUE FROM VALUE NORMAL .............................................................. TEMPERATURE (F) RECORD HIGH 99 09/11/1983 09/10/1983 09/02/1980 LOW 30 09/24/1974 HIGHEST 89 09/08 91 -2 91 09/14 09/15 LOWEST 45 09/30 39 6 38 AVG. MAXIMUM 80.8 79.3 1.5 77.3 AVG. MINIMUM 59.1 57.9 1.2 57.1 MEAN 69.9 68.6 1.3 67.2 DAYS MAX >= 90 0 3.1 -3.1 1 DAYS MAX <= 32 0 0.0 0.0 0 DAYS MIN <= 32 0 0.0 0.0 0 DAYS MIN <= 0 0 0.0 0.0 0 PRECIPITATION (INCHES) RECORD MAXIMUM 11.26 1975 MINIMUM 0.15 2005 TOTALS 4.72 3.94 0.78 2.28 DAILY AVG. 0.16 0.13 0.03 0.08 DAYS >= .01 8 9.0 -1.0 11 DAYS >= .10 5 5.9 -0.9 8 DAYS >= .50 3 2.5 0.5 1 DAYS >= 1.00 2 1.2 0.8 0 GREATEST 24 HR. TOTAL 1.95 08/31 TO 09/01 0.88 STORM TOTAL 1.93 0.77 (MM/DD(HH)) SNOWFALL (INCHES) RECORDS TOTAL MM MM TOTALS 0.0 0.0 0.0 0.0 SINCE 7/1 0.0 0.0 0.0 MM DAYS >= TRACE 0 0.0 0.0 0 DAYS >= 1.0 0 0.0 0.0 0 GREATEST SNOW DEPTH 0 0 DEGREE DAYS HEATING TOTAL 17 45 -28 61 SINCE 7/1 17 44 -27 MM COOLING TOTAL 171 152 19 135 SINCE 1/1 1423 1208 215 MM .............................................................. WIND (MPH) AVERAGE WIND SPEED 5.9 HIGHEST WIND SPEED/DIRECTION 24/150 HIGHEST GUST SPEED/DIRECTION 37/160 SKY COVER AVERAGE SKY COVER 0.44 AVERAGE RH (PERCENT) 71 WEATHER CONDITIONS. NUMBER OF DAYS WITH THUNDERSTORM 7 MIXED PRECIP 0 HEAVY RAIN 3 RAIN 6 LIGHT RAIN 10 FREEZING RAIN 0 LT FREEZING RAIN 0 HAIL 0 HEAVY SNOW 0 SNOW 0 LIGHT SNOW 0 SLEET 0 FOG 11 FOG W/VIS <= 1/4 MILE 0 HAZE 0 - INDICATES NEGATIVE NUMBERS. R INDICATES RECORD WAS SET OR TIED. MM INDICATES DATA IS MISSING. T INDICATES TRACE AMOUNT. && ..................................................................... WASHINGTON DULLES INTERNATIONAL AIRPORT... THE AVERAGE TEMPERATURE IN SEPTEMBER 2021 WAS ABOVE NORMAL. IT WAS THE WARMEST SEPTEMBER SINCE 2019, WHEN THE AVERAGE TEMPERATURE WAS 72.5 DEGREES. TOTAL PRECIPITATION WAS 120 PERCENT OF NORMAL. IT WAS THE WETTEST SEPTEMBER SINCE 2018, WHEN 7.36 INCHES OF PRECIPITATION FELL. A RECORD WARM LOW TEMPERATURE WAS SET ON SEPTEMBER 16TH WHEN THE LOW WAS ONLY 69 DEGREES. THIS TIED THE RECORD LAST SET IN 2005. WEATHER RECORDS FOR THE DULLES VA AREA HAVE BEEN RECORDED AT WHAT IS NOW WASHINGTON DULLES INTERNATIONAL AIRPORT SINCE 1960. THE OFFICIAL RECORD CONSISTS SOLELY OF DATA RECORDED AT THE AIRPORT. TEMPERATURE AND PRECIPITATION RECORDS BEGAN IN 1960. SNOWFALL RECORDS BEGAN IN 1962. ALL CLIMATE DATA ARE CONSIDERED PRELIMINARY UNTIL REVIEWED BY THE NATIONAL CENTERS FOR ENVIRONMENTAL INFORMATION (NCEI). $$ RCM

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