January weather forecastCastleton, IL
January
Weather in January
January, like December, is another subzero cold winter month in Castleton, Illinois, with an average temperature fluctuating between 17.8°F (-7.9°C) and 29.7°F (-1.3°C).Temperature
Castleton, Illinois, records the coldest temperatures in January, averaging a high of 29.7°F (-1.3°C) and a low of 17.8°F (-7.9°C).Humidity
In Castleton, the average relative humidity in January is 82%.Rainfall
The month with the least rainfall is January, when the rain falls for 4.2 days and typically collects 0.59" (15mm) of precipitation.Snowfall
Months with snowfall in Castleton, Illinois, are January through April, October through December. The month with the most snowfall is January, when snow falls for 8.6 days and typically aggregates up to 1.81" (46mm) of snow.Daylight
The average length of the day in January in Castleton is 9h and 37min.On the first day of January in Castleton, sunrise is at 7:23 am and sunset at 4:40 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 5:13 pm CST.
Sunshine
With an average of 3.9h of sunshine, January has the least sunshine of the year.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for the average person.Note: The maximum UV index of 1 during January translates into these guidelines:
While most people can stay under the sun for an hour without burning, children must always be guarded against sun exposure. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Employ a wide-brim hat for potent defense against up to 50% of UV rays. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Castleton, IL
- Average high temperature in January: 29.7°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in January: 17.8°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (17.8°F).
Average pressure in January
Castleton, IL
- Average pressure in January: 30.14"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in January
Castleton, IL
- Average wind speed in January: 10.5mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in January
Castleton, IL
- Average humidity in January: 82%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).
Average rainfall in January
Castleton, IL
- Average rainfall in January: 0.59"
The wettest month (with the highest rainfall) is May (2.24").
The driest month (with the least rainfall) is January (0.59").
Average rainfall days in January
Castleton, IL
- Average rainfall days in January: 4.2 days
The month with the highest number of rainy days is May (15.2 days).
The months with the least rainy days are January and February (4.2 days).
Average snowfall in January
Castleton, IL
- Average snowfall in January: 1.81"
The month with the highest snowfall is January (1.81").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in January
Castleton, IL
- Average snowfall days in January: 8.6 days
The month with the highest number of snowfall days is January (8.6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in January /
Average sunshine in January
Castleton, IL
- Average daylight in January: 9h and 36min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in January: 3h and 54min
The months with the most sunshine are June and July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in January
Castleton, IL
- Average sunshine days in January: 19.8 days
The month with the most sunshine days is November (21.3 days).
The month with the least sunshine days is May (12.8 days).
Average UV index in January
Castleton, IL
- Average UV index in January: 1
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in January
Castleton, IL
- Average cloud cover in January: 58
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility in January
Castleton, IL
- Average visibility in January: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
