May weather forecastCharleston, IL
May
Weather in May
The last month of the spring, May, is an agreeable month in Charleston, Illinois, with temperature in the range of an average high of 73°F (22.8°C) and an average low of 56.7°F (13.7°C).Temperature
Charleston's transition into May is marked by a temperature shift, moving from a comfortable 62.2°F (16.8°C) in April to an agreeable 73°F (22.8°C). During the May nights, an average temperature of 56.7°F (13.7°C) is observed.Humidity
In May, the average relative humidity is 79%.Rainfall
In Charleston, in May, it is raining for 16.8 days, with typically 2.87" (73mm) of accumulated precipitation. Throughout the year, there are 148 rainfall days, and 25.63" (651mm) of precipitation is accumulated.Snowfall
In Charleston, snow does not fall in May through September.Daylight
In Charleston, the average length of the day in May is 14h and 22min.On the first day of May, sunrise is at 5:52 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 5:27 am and sunset at 8:13 pm CDT.
Sunshine
In May, the average sunshine is 8.8h.UV index
In Charleston, the average daily maximum UV index in May is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the ordinary person.Note: An average maximum UV index of 5 in May leads to these recommendations:
Prioritize safety - The need to safeguard skin and eyes from harm is emphasized. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Charleston, IL
- Average high temperature in May: 73°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (34°F).
- Average low temperature in May: 56.7°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 (21.9°F).
Average pressure in May
Charleston, IL
- Average pressure in May: 29.96"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 May
Charleston, IL
- Average wind speed in May: 8.6mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest month (with the lowest average wind speed) is July (6.2mph).
Average humidity in May
Charleston, IL
- Average humidity in May: 79%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (70%).
Average rainfall in May
Charleston, IL
- Average rainfall in May: 2.87"
The wettest month (with the highest rainfall) is April (3.31").
The driest month (with the least rainfall) is February (1.3").
Average rainfall days in May
Charleston, IL
- Average rainfall days in May: 16.8 days
The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is February (7.8 days).
Average snowfall in May
Charleston, IL
- Average snowfall in May: 0"
The month with the highest snowfall is December (2.13").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in May
Charleston, IL
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (8.1 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Charleston, IL
- Average daylight in May: 14h and 24min
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 May: 8h and 48min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in May
Charleston, IL
- Average sunshine days in May: 11.2 days
The month with the most sunshine days is October (18.3 days).
The month with the least sunshine days is July (10.6 days).
Average UV index in May
Charleston, IL
- Average UV index in May: 5
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in May
Charleston, IL
- Average cloud cover in May: 41
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is June (Cloud cover 31).
Average visibility in May
Charleston, IL
- Average visibility in May: 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).





