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000
CXUS51 KLWX 040008
CLMIAD

CLIMATE REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
808 PM EDT FRI MAY 3 2013

...................................

...THE WASHINGTON DULLES DC CLIMATE SUMMARY FOR THE MONTH OF APRIL 2013...

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1962 TO 2013

WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR`S
                 VALUE   DATE(S)  VALUE   FROM    VALUE
                                          NORMAL
.............................................................
TEMPERATURE (F)
RECORD
 HIGH              93   04/06/2010
                        04/17/2002
 LOW               17   04/01/1969
HIGHEST            89   04/10        85       4
LOWEST             22   04/04        25      -3
AVG. MAXIMUM     67.7              66.7     1.0     66.5
AVG. MINIMUM     44.5              42.1     2.4     41.6
MEAN             56.1              54.4     1.7
DAYS MAX >= 90      0               0.3    -0.3
DAYS MAX <= 32      0               0.0     0.0
DAYS MIN <= 32      3               3.9    -0.9
DAYS MIN <= 0       0               0.0     0.0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM         7.35   1973
 MINIMUM         0.33   1985
TOTALS           2.30              3.47   -1.17     1.82
DAILY AVG.       0.08              0.12   -0.04
DAYS >= .01         8              10.7    -2.7
DAYS >= .10         4               6.8    -2.8
DAYS >= .50         2               2.0     0.0
DAYS >= 1.00        1               0.8     0.2
GREATEST
 24 HR. TOTAL    1.20   04/19

SNOWFALL (INCHES)
RECORDS
 TOTAL            4.0   1990
TOTALS            0.0               0.3    -0.3
SINCE 7/1        12.7              22.0    -9.3
SNOWDEPTH AVG.      0
DAYS >= TRACE       0               0.3    -0.3
DAYS >= 1.0         0               0.1    -0.1
GREATEST
 SNOW DEPTH         0
 24 HR TOTAL      0.0

DEGREE_DAYS
HEATING TOTAL     288               335     -47      340
 SINCE 7/1       4414              4572    -158     3729
COOLING TOTAL      30                17      13       18
 SINCE 1/1         30                20      10       28
..............................................................

WIND (MPH)
AVERAGE WIND SPEED              7.7
HIGHEST WIND SPEED/DIRECTION    31/310    DATE  04/24
HIGHEST GUST SPEED/DIRECTION    39/310    DATE  04/24

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.60
NUMBER OF DAYS FAIR            4
NUMBER OF DAYS PC             17
NUMBER OF DAYS CLOUDY          9

AVERAGE RH (PERCENT)     58

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              1     MIXED PRECIP               0
HEAVY RAIN                2     RAIN                       3
LIGHT RAIN               10     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                       9     FOG W/VIS <= 1/4 MILE      2
HAZE                      2

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.

&&

AFTER TWO STRAIGHT MONTHS OF BELOW NORMAL TEMPERATURES...THE MONTHLY
AVERAGE TEMPERATURE FOR APRIL WAS ALMOST TWO DEGREES ABOVE THE
1981-2010 NORMAL. HOWEVER...THE MONTH ENDED ON A COOL NOTE AS 10 OF
THE LAST 11 DAYS RECORDED BELOW NORMAL AVERAGE TEMPERATURES.

A WINTER-LIKE COLD PERIOD OCCURRED DURING THE 2ND-4TH. IN
PARTICULAR...THE LOW TEMPERATURE WAS 24 DEGREES ON THE 3RD AND 22
DEGREES ON THE 4TH. IT WAS ONLY THE FOURTH OCCURRENCE ON RECORD THAT
HAD CONSECUTIVE DAYS WITH A LOW TEMPERATURE BELOW 25 DEGREES IN
APRIL AND THE FIRST IN APRIL SINCE 9-10 APRIL 1977.

THE LOW TEMPERATURE OF 22 DEGREES ON THE 4TH TIED THE DAILY RECORD
LOW FOR DULLES THAT WAS PREVIOUSLY SET IN 1965. IT WAS THE LOWEST
TEMPERATURE DURING APRIL SINCE 7 APRIL 2002 WHEN IT WAS ALSO 22
DEGREES.

A SUMMER-LIKE PERIOD FROM THE 8TH-11TH FEATURED FOUR STRAIGHT DAYS
OF AT LEAST 80 DEGREES. 2013 WAS ONLY THE SECOND YEAR ON RECORD THAT
RECORDED FOUR CONSECUTIVE 80-DEGREE DAYS THROUGH THE FIRST HALF OF
APRIL /THE OTHER WAS 5-8 APRIL 2010/.

THE HIGH TEMPERATURE OF 89 DEGREES ON THE 10TH SET A DAILY RECORD
HIGH FOR DULLES. IT BROKE THE OLD RECORD OF 78 SET IN 1922.

RAINFALL FOR THE MONTH WAS BELOW NORMAL. HALF OF THE MONTHLY
PRECIPITATION FELL ON THE 19TH.

$$
JRK/SMZ