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
In Williamson, January is the coldest month, with temperatures averaging a high of 35.6°F (2°C) and a low of 22.6°F (-5.2°C).Humidity
In January, the average relative humidity is 77%.Rainfall
In Williamson, during January, the rain falls for 5.8 days and regularly aggregates up to 1.02" (26mm) of precipitation. In Williamson, during the entire year, the rain falls for 121.4 days and collects up to 14.72" (374mm) of precipitation.Snowfall
Months with snowfall are January through March, November and December. In Williamson, in January, snow falls for 6.3 days, with typically accumulated 0.63" (16mm) of snow. In Williamson, during the entire year, snow falls for 19.8 days and aggregates up to 2.91" (74mm) of snow.Daylight
In Williamson, the average length of the day in January is 9h and 48min.On the first day of January, sunrise is at 7:17 am and sunset at 4:47 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 5:18 pm CST.
Sunshine
January has the least sunshine of the year, with an average of 4.4h of sunshine.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a low threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: In January, a daily UV index of 2 turns into the following recommendations:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. 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
What is the coldest month?
How cold is January?
What is the average humidity in January?
How many days does it rain in January?
How much does it snow in January?
How many hours of daylight does Williamson have in January?
When are sunrise and sunset in January?
What is the month with the least sunshine?
How long on average sun shines in January?
What are the months with the lowest UV index?
How high is the UV index in January?
Average temperature in January
Williamson, IL
- Average high temperature in January: 35.6°F
The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.6°F).
- Average low temperature in January: 22.6°F
The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).
Average pressure in January
Williamson, IL
- Average pressure in January: 30.16"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in January
Williamson, IL
- Average wind speed in January: 10mph
The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).
Average humidity in January
Williamson, IL
- Average humidity in January: 77%
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in January
Williamson, IL
- Average rainfall in January: 1.02"
The wettest month (with the highest rainfall) is June (1.89").
The driest month (with the least rainfall) is February (0.67").
Average rainfall days in January
Williamson, IL
- Average rainfall days in January: 5.8 days
The month with the highest number of rainy days is July (14 days).
The month with the least rainy days is January (5.8 days).
Average snowfall in January
Williamson, IL
- Average snowfall in January: 0.63"
The month with the highest snowfall is December (0.98").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in January
Williamson, IL
- Average snowfall days in January: 6.3 days
The month with the highest number of snowfall days is January (6.3 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
Williamson, 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 30min).
- Average sunshine in January: 4h and 2min
The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in January
Williamson, IL
- Average sunshine days in January: 20.9 days
The month with the most sunshine days is January (20.9 days).
The month with the least sunshine days is July (12.5 days).
Average UV index in January
Williamson, 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
Williamson, IL
- Average cloud cover in January: 52
The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).
Average visibility in January
Williamson, IL
- Average visibility in January: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Williamson, Illinois, USA
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