Contents
- Weather in January
- Frequently asked questions
- Average temperature in January
- Average pressure in January
- Average wind speed in January
- Average humidity in January
- Average rainfall in January
- Average rainfall days in January
- Average snowfall in January
- Average snowfall days in January
- Average daylight in January
- Average sunshine in January
- Average sunshine days in January
- Average UV index in January
- Average cloud cover in January
- Average visibility in January
Weather in January
Temperature
The lowest temperatures in Herndon, Virginia, are recorded in January, with averages reaching a high of 39.7°F (4.3°C) and a low of 25.9°F (-3.4°C).Humidity
The average relative humidity in January is 74%.Rainfall
In Herndon, in January, it is raining for 9.3 days, with typically 2.13" (54mm) of accumulated precipitation. Throughout the year, there are 158.1 rainfall days, and 31.46" (799mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, November and December. January is the month with the most snowfall. Snow falls for 5.1 days and accumulates 3.54" (90mm) of snow.Daylight
The average length of the day in January is 9h and 48min.On the first day of January, sunrise is at 7:28 am and sunset at 4:57 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 5:29 pm EST.
Sunshine
January, February and December, with an average of 5h of sunshine, are months with the least 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: In January, the UV index of 2 transforms into the following advice:
Most individuals face no major issues with lengthy exposure to the sun, but children, infants, and individuals with fair skin always require protection. Avoiding the Sun during its peak radiation time around midday is a healthy practice. During bright days, sunglasses that offer UVA and UVB defense are recommended. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the coldest month in Herndon?
Is it cold during January?
What is the average humidity in January?
How much does it rain in January?
What is the snowiest month?
How much does it snow in January?
What is the average length of the day in January?
What time are sunrise and sunset in January?
What are the months with the least sunshine in Herndon?
How many hours of sunshine does Herndon have in January?
What is the month with the lowest UV index?
How high is the UV index in January?
Average temperature in January
Herndon, VA
- Average high temperature in January: 39.7°F
The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is January (39.7°F).
- Average low temperature in January: 25.9°F
The month with the highest average low temperature is July (67.3°F).
The coldest month (with the lowest average low temperature) is January (25.9°F).
Average pressure in January
Herndon, 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
Herndon, VA
- Average wind speed in January: 7.2mph
The windiest month (with the highest average wind speed) is March (7.5mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in January
Herndon, VA
- Average humidity in January: 74%
The month with the highest relative humidity is December (78%).
The month with the lowest relative humidity is July (70%).
Average rainfall in January
Herndon, VA
- Average rainfall in January: 2.13"
The wettest month (with the highest rainfall) is August (3.78").
The driest month (with the least rainfall) is September (1.93").
Average rainfall days in January
Herndon, VA
- Average rainfall days in January: 9.3 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (9.3 days).
Average snowfall in January
Herndon, VA
- Average snowfall in January: 3.54"
The month with the highest snowfall is January (3.54").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in January
Herndon, VA
- Average snowfall days in January: 5.1 days
The months with the highest number of snowfall days are January and February (5.1 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
Herndon, VA
- Average daylight in January: 9h and 5min
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
Herndon, VA
- Average sunshine days in January: 17.2 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (11.8 days).
Average UV index in January
Herndon, 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
Herndon, VA
- Average cloud cover in January: 46
The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in January
Herndon, 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).
Herndon, Virginia, USA
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