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
Sullivan's January weather reaches an average high of 33.6°F (0.9°C) and an average low of 21.6°F (-5.8°C), making it the coldest month.Humidity
In January, the average relative humidity is 79%.Rainfall
In Sullivan, Illinois, in January, it is raining for 6.4 days, with typically 0.94" (24mm) of accumulated precipitation. Throughout the year, there are 130.9 rainfall days, and 15.43" (392mm) of precipitation is accumulated.Snowfall
January through April, November and December are months with snowfall. The month with the most snowfall is January, when snow falls for 6.4 days and typically aggregates up to 1.54" (39mm) of snow.Daylight
The average length of the day in January in Sullivan is 9h and 45min.On the first day of the month, sunrise is at 7:14 am and sunset at 4:40 pm. On the last day of January, sunrise is at 7:03 am and sunset at 5:12 pm CST.
Sunshine
The month with the least sunshine is January, with an average of 4.1h of sunshine.UV index
The months with the lowest UV index in Sullivan are January, February, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: The average daily UV index of 2 in January transforms into the following instructions:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the coldest time of year in Sullivan?
How cold is January in Sullivan?
What is the average humidity in January in Sullivan?
How much does it rain in Sullivan in January?
What is the snowiest month in Sullivan?
How much does it snow in Sullivan in January?
What is the average length of the day in January in Sullivan?
When is the sunrise / sunset in January in Sullivan?
What is the month with the least sunshine in Sullivan?
How many hours of sunshine does Sullivan have in January?
What are the months with the lowest UV index in Sullivan?
What is the UV index reading in January in Sullivan?
Average temperature in January
Sullivan, IL
- Average high temperature in January: 33.6°F
The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (33.6°F).
- Average low temperature in January: 21.6°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).
Average pressure in January
Sullivan, IL
- Average pressure in January: 30.15"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in January
Sullivan, IL
- Average wind speed in January: 10.7mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.3mph).
Average humidity in January
Sullivan, IL
- Average humidity in January: 79%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (70%).
Average rainfall in January
Sullivan, IL
- Average rainfall in January: 0.94"
The wettest month (with the highest rainfall) is June (1.85").
The driest month (with the least rainfall) is February (0.71").
Average rainfall days in January
Sullivan, IL
- Average rainfall days in January: 6.4 days
The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is February (5.9 days).
Average snowfall in January
Sullivan, IL
- Average snowfall in January: 1.54"
The month with the highest snowfall is January (1.54").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in January
Sullivan, IL
- Average snowfall days in January: 6.4 days
The month with the highest number of snowfall days is January (6.4 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
Sullivan, IL
- 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 24min).
- Average sunshine in January: 4h and 1min
The month with the most sunshine is June (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in January
Sullivan, IL
- Average sunshine days in January: 19.8 days
The month with the most sunshine days is October (20.5 days).
The month with the least sunshine days is May (12.3 days).
Average UV index in January
Sullivan, IL
- Average UV index in January: 2
The months with the highest UV index are 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
Sullivan, IL
- Average cloud cover in January: 56
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is June (Cloud cover 30).
Average visibility in January
Sullivan, 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).
Sullivan, Illinois, USA
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