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CXUS51 KLWX 020251
CLMIAD
CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
951 PM EST SUN NOV 1 2009
...............................
...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR THE MONTH OF OCTOBER 2009...
CLIMATE NORMAL PERIOD 1971 TO 2000
CLIMATE RECORD PERIOD 1962 TO 2009
WEATHER OBSERVED NORMAL DEPART LAST YEAR'S
VALUE DATE(S) VALUE FROM VALUE
NORMAL
.........................................................
TEMPERATURE (F)
RECORD
HIGH 94 10/09/2007
LOW 15 10/24/1969
HIGHEST 87 10/09 83 4
LOWEST 33 10/19 27 6
AVG. MAXIMUM 66.1 67.7 -1.6 66.5
AVG. MINIMUM 46.6 42.3 4.3 43.8
MEAN 56.4 55.0 1.4
DAYS MAX >= 90 0 0.0 0.0
DAYS MAX <= 32 0 0.0 0.0
DAYS MIN <= 32 0 4.9 -4.9
DAYS MIN <= 0 0 0.0 0.0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 9.22 2005
MINIMUM T 1963
TOTALS 5.70 3.37 2.33 1.31
DAILY AVG. 0.18 0.11 0.07
DAYS >= .01 12 7.8 4.2
DAYS >= .10 7 5.0 2.0
DAYS >= .50 5 2.3 2.7
DAYS >= 1.00 2 0.9 1.1
GREATEST
24 HR. TOTAL 1.73 10/23 TO 10/24
SNOWFALL (INCHES)
RECORDS
TOTAL 1.3 1979 TOTALS 0.0 0.1 -0.1
TOTALS 0.0 0.1 -0.1
SINCE 7/1 0.0 0.1 -0.1
SNOWDEPTH AVG. 0
DAYS >= TRACE 0 0.1 -0.1
DAYS >= 1.0 0 0.0 0.0
GREATEST
SNOW DEPTH 0 MM
24 HR TOTAL 0.0
DEGREE_DAYS
HEATING TOTAL 268 323 -55 314
SINCE 7/1 287 388 -101 338
COOLING TOTAL 8 15 -7 17
SINCE 1/1 1259 1072 187 1171
..........................................................
WIND (MPH)
AVERAGE WIND SPEED 6.8
HIGHEST WIND SPEED/DIRECTION 32/300 DATE 10/07
HIGHEST GUST SPEED/DIRECTION 45/280 DATE 10/07
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
NUMBER OF DAYS FAIR 4
NUMBER OF DAYS PC 11
NUMBER OF DAYS CLOUDY 16
AVERAGE RH (PERCENT) 68
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 1 MIXED PRECIP 0
HEAVY RAIN 3 RAIN 7
LIGHT RAIN 17 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 0 SLEET 0
FOG 15 FOG W/VIS <= 1/4 MILE 1
HAZE 7
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
THE AVERAGE MONTHLY TEMPERATURE WAS SLIGHTLY ABOVE NORMAL...MAINLY
DUE TO THE LOW TEMPERATURE BEING WELL ABOVE NORMAL. A READING OF 87F
ON THE 9TH TIED FOR THE SECOND WARMEST HIGH TEMPERATURE FOR THAT DAY.
A SLOW MOVING STORM SYSTEM BROUGHT CLOUDY...WET AND VERY COOL
CONDITIONS DURING THE MIDDLE OF THE MONTH. THE HIGH TEMPERATURE
FAILED TO REACH 50F DURING A THREE DAY-PERIOD BETWEEN OCTOBER
15-17...WHICH TIED FOR THE LONGEST STRETCH OF CONSECUTIVE DAYS NOT
REACHING 50F DURING ANY OCTOBER AT DULLES SINCE 1962.
DULLES HAD ABOVE NORMAL PRECIPITATION THIS MONTH FOR THE FIRST TIME
SINCE JUNE 2009. IT WAS THE 8TH WETTEST OCTOBER ON RECORD. WETTER
THAN NORMAL CONDITIONS HAVE OCCURRED SIX OUT OF THE LAST EIGHT
OCTOBERS. AT LEAST 0.50 INCHES OF PRECIPITATION FELL ON SIX DAYS
THIS MONTH...WHICH TIED FOR THE MOST OCCURRENCES OF HALF INCH OR
HIGHER RAINFALL EVENTS FOR ANY OCTOBER SINCE 1976.
RAINFALL OF 1.69 INCHES ON THE 24TH SET A DAILY RECORD FOR THE DATE
AT DULLES.
JRK/SMZ
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