Contents
- Weather in April
- Frequently asked questions
- Average temperature in April
- Average pressure in April
- Average wind speed in April
- Average humidity in April
- Average rainfall in April
- Average rainfall days in April
- Average snowfall in April
- Average snowfall days in April
- Average daylight in April
- Average sunshine in April
- Average sunshine days in April
- Average UV index in April
- Average cloud cover in April
- Average visibility in April
Weather in April
Temperature
April's onset brings a temperature rise, moving from a fresh 52.3°F (11.3°C) in March to an enjoyable 63.9°F (17.7°C). During April, Williamson's temperature averages to a frosty 46.6°F (8.1°C) at night.Humidity
In April, the average relative humidity is 76%.Rainfall
In April, the rain falls for 12.5 days. Throughout April, 1.57" (40mm) of precipitation is accumulated. Throughout the year, there are 121.4 rainfall days, and 14.72" (374mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall.Daylight
The average length of the day in April is 13h and 15min.On the first day of the month, sunrise is at 6:42 am and sunset at 7:23 pm. On the last day of April, sunrise is at 6:01 am and sunset at 7:51 pm CDT.
Sunshine
In Williamson, the average sunshine in April is 8.3h.UV index
The average daily maximum UV index in April is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: The daily maximum UV index of 4 in April interprets into the following advice:
Be vigilant - Suggestions to stave off sun damage are provided. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. 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 are April temperatures?
What is the average humidity in April?
How much does it rain in April?
When it does not snow?
Does it snow in April?
How many hours of daylight does Williamson have in April?
When is the sunrise / sunset in April in Williamson?
How long on average sun shines in April in Williamson?
What is the UV index intensity in April?
Average temperature in April
Williamson, IL
- Average high temperature in April: 63.9°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 April: 46.6°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 April
Williamson, IL
- Average pressure in April: 29.94"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 April
Williamson, IL
- Average wind speed in April: 9.6mph
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 April
Williamson, IL
- Average humidity in April: 76%
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in April
Williamson, IL
- Average rainfall in April: 1.57"
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 April
Williamson, IL
- Average rainfall days in April: 12.5 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 April
Williamson, IL
- Average snowfall in April: 0"
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 April
Williamson, IL
- Average snowfall days in April: 0.3 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 April /
Average sunshine in April
Williamson, IL
- Average daylight in April: 13h and 2min
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 April: 8h 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 April
Williamson, IL
- Average sunshine days in April: 14.6 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 April
Williamson, IL
- Average UV index in April: 4
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 April
Williamson, IL
- Average cloud cover in April: 43
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 April
Williamson, IL
- Average visibility in April: 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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