January weather forecastReston, VA
January
Weather in January
January, like December, in Reston, Virginia, is an icy winter month, with an average temperature ranging between max 39.7°F (4.3°C) and min 26.4°F (-3.1°C).Temperature
Reston's January weather, with an average high temperature of 39.7°F (4.3°C) and an average low temperature of 26.4°F (-3.1°C), tends to be the coldest of the year.Humidity
The average relative humidity in January is 73%.Rainfall
The month with the least rainfall is January, when the rain falls for 9.4 days and typically collects 1.77" (45mm) of precipitation.Snowfall
Months with snowfall are January through April, November and December. The month with the most snowfall is January, when snow falls for 4.6 days and typically aggregates up to 2.28" (58mm) of snow.Daylight
The average length of the day in January is 9h and 48min.On the first day of the month, sunrise is at 7:28 am and sunset at 4:57 pm. On the last day of January, in Reston, sunrise is at 7:16 am and sunset at 5:28 pm EST.
Sunshine
The months with the least sunshine are January, February and December, with an average of 5h of sunshine.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a low threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum daily UV index of 2 in January interprets into the following recommendations:
Extended sunlight exposure does not pose significant problems for most people, except for children, infants, and people with fair skin who always need shielding. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Reston, VA
- Average high temperature in January: 39.7°F
The warmest month (with the highest average high temperature) is July (87.6°F).
The month with the lowest average high temperature is January (39.7°F).
- Average low temperature in January: 26.4°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.4°F).
Average pressure in January
Reston, VA
- Average pressure in January: 30.11"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in January
Reston, VA
- Average wind speed in January: 7.4mph
The windiest month (with the highest average wind speed) is March (7.7mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).
Average humidity in January
Reston, VA
- Average humidity in January: 73%
The months with the highest relative humidity are October and December (76%).
The month with the lowest relative humidity is July (69%).
Average rainfall in January
Reston, VA
- Average rainfall in January: 1.77"
The wettest month (with the highest rainfall) is August (3.39").
The driest month (with the least rainfall) is January (1.77").
Average rainfall days in January
Reston, VA
- Average rainfall days in January: 9.4 days
The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is November (9.3 days).
Average snowfall in January
Reston, VA
- Average snowfall in January: 2.28"
The month with the highest snowfall is January (2.28").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in January
Reston, VA
- Average snowfall days in January: 4.6 days
The month with the highest number of snowfall days is January (4.6 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in January /
Average sunshine in January
Reston, VA
- Average daylight in January: 9h and 48min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in January: 5h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 0min).
Average sunshine days in January
Reston, VA
- Average sunshine days in January: 17.8 days
The month with the most sunshine days is November (19.3 days).
The month with the least sunshine days is May (12.8 days).
Average UV index in January
Reston, VA
- Average UV index in January: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in January
Reston, VA
- Average cloud cover in January: 45
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in January
Reston, VA
- Average visibility in January: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
