January weather forecastHerndon, PA
January
Weather in January
January, like December, in Herndon, Pennsylvania, is a wintry winter month, with an average temperature ranging between min 20.1°F (-6.6°C) and max 32.9°F (0.5°C).Temperature
January is the month that records the lowest temperatures, with averages ranging from a high of 32.9°F (0.5°C) to a low of 20.1°F (-6.6°C).Humidity
The average relative humidity in January is 79%.Rainfall
In Herndon, in January, it is raining for 9.3 days, with typically 2.2" (56mm) of accumulated precipitation. In Herndon, during the entire year, the rain falls for 165.3 days and collects up to 30.55" (776mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In January, it is snowing for 11.3 days. Throughout January, 4.41" (112mm) of snow is accumulated. In Herndon, during the entire year, snow falls for 38.1 days and aggregates up to 17.68" (449mm) of snow.Daylight
In Herndon, the average length of the day in January is 9h and 39min.On the first day of January, sunrise is at 7:31 am and sunset at 4:50 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 5:23 pm EST.
Sunshine
In January, the average sunshine in Herndon is 4.3h.UV index
The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low threat to health from exposure to the Sun's UV radiation for average individuals.Note: A maximum high UV index of 2 in January translates into the following recommendations:
Apart from children, who require continuous protection, most can endure sun exposure for up to an hour without experiencing burns. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Herndon, PA
- Average high temperature in January: 32.9°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (32.9°F).
- Average low temperature in January: 20.1°F
The month with the highest average low temperature is July (61.2°F).
The coldest month (with the lowest average low temperature) is January (20.1°F).
Average pressure in January
Herndon, PA
- Average pressure in January: 30.09"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in January
Herndon, PA
- Average wind speed in January: 7.5mph
The windiest months (with the highest average wind speed) are March and April (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in January
Herndon, PA
- Average humidity in January: 79%
The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is April (76%).
Average rainfall in January
Herndon, PA
- Average rainfall in January: 2.2"
The wettest month (with the highest rainfall) is May (3.35").
The driest months (with the least rainfall) are February and November (2.09").
Average rainfall days in January
Herndon, PA
- Average rainfall days in January: 9.3 days
The month with the highest number of rainy days is May (18.4 days).
The month with the least rainy days is February (9 days).
Average snowfall in January
Herndon, PA
- Average snowfall in January: 4.41"
The month with the highest snowfall is February (5.67").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in January
Herndon, PA
- Average snowfall days in January: 11.3 days
The month with the highest number of snowfall days is January (11.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in January /
Average sunshine in January
Herndon, PA
- Average daylight in January: 9h and 42min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in January: 4h and 18min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 12min).
Average sunshine days in January
Herndon, PA
- Average sunshine days in January: 13.9 days
The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is May (9.9 days).
Average UV index in January
Herndon, PA
- Average UV index in January: 2
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in January
Herndon, PA
- Average cloud cover in January: 53
The month with the most cloud cover is February (Cloud cover 54).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in January
Herndon, PA
- Average visibility in January: 5mi
The months with the highest visibility are March, April, June, July and November (6mi).
The months with the lowest visibility are January, February, May, August, September, October and December (5mi).
