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United States of America

HERNDON, VIRGINIA


Home > North America > United States > Virginia
Elevation: 322 feet     Latitude: 38 57N     Longitude: 077 27W

WEATHER
 
CURRENT CONDITIONS

As of 25 September, 2018 @ 12:56 pm EDT
(64 Minutes Ago)

Mist
Temperature
73.4°F
Humidity
94.1 %
Wind
4.6 mph
Sunrise/Set
07:00 am
07:01 pm
Visibility
6 mi
Dew Point
71.6 °F
Pressure
30.21 in hg
Local Time
2:00 pm EDT
25 September, 2018
 
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MONTHLY - ALL WEATHER AVERAGES   [ Show Summary ]
[ °C ]   °F
TEMPERATURE 
Average Temperature
Years on Record: 37  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
F51323342516069757366534435

Average High Temperature
Years on Record: 37  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
F64414253647382868478665544

Average Low Temperature
Years on Record: 37  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
F41232432395059646255413326



PRECIPITATION 
Average Precipitation
Years on Record: 36  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
in39.92.82.83.43.13.83.43.43.93.53.23.43.2



DEGREE DAYS 
Heating Degree Days
Years on Record: 37  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days5054.51023904697.5405108.5------------356.5630930

Cooling Degree Days
Years on Record: 37  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days768---------------16531024845---------

Growing Degree Days
Years on Record: 37  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days3108---------45356.5615775713495108.5------



SKY CONDITIONS 
Average Length of Day
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Hours12.710.311.212.413.714.815.415.114.112.811.610.510



SOLAR RADIATION 
Average Daily Solar Radiation - Global
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m23.922.83.74.75.35.65.654.33.42.21.7

Average Daily Solar Radiation - Diffuse
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m21.60.81.11.522.32.52.42.11.71.20.90.7

Average Daily Solar Radiation - Reflected
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m24.33.13.74.34.74.94.954.84.74.53.42.9

Average Daily Solar Radiation - Direct
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m24.23.13.74.14.44.74.84.94.64.64.63.52.9

Maximum Daily Solar Radiation - Global
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m23.922.83.74.75.35.65.654.33.42.21.7

Maximum Daily Solar Radiation - Diffuse
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m21.70.81.21.62.12.42.52.52.21.71.30.90.8

Maximum Daily Solar Radiation - Reflected
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m253.74.65.35.45.85.75.45.45.55.74.33.4

Maximum Daily Solar Radiation - Direct
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m25.43.95.25.55.66.46.65.85.666.44.83.6

Minimum Daily Solar Radiation - Global
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m23.21.72.2343.54.754.43.72.71.61.3

Minimum Daily Solar Radiation - Diffuse
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m21.50.811.41.92.22.32.321.510.80.7

Minimum Daily Solar Radiation - Reflected
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m23.42.52.83.443.34.24.54.23.93.42.22

Minimum Daily Solar Radiation - Direct
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m22.82.32.42.73.323.43.93.63.431.91.8




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WEATHER FORECAST

As of 3:49 am 9/25/18 EDT

Tuesday
Drizzle
76°
69°
Wednesday
Partly Cloudy
84°
62°
Thursday
Cloudy
70°
59°
Friday
Cloudy
73°
64°
Saturday
Light Clouds
79°
55°
Sunday
Clear
66°
51°
Monday
Light Clouds
71°
55°

Forecast data from The Norwegian Meteorological Institute; Current conditions data from the National Weather Service
All historical data and normals © Weatherbase


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