May weather forecastSaint Charles, IA
May
Weather in May
May, the last month of the spring in Saint Charles, is an agreeable month, with temperature in the range of an average low of 52.7°F (11.5°C) and an average high of 69.4°F (20.8°C).Temperature
With the onset of May, Saint Charles's average high-temperature experiences a rise, moving from April's refreshing 59.7°F (15.4°C) to an agreeable 69.4°F (20.8°C). Saint Charles records an average low of 52.7°F (11.5°C) throughout the nights in May.Humidity
The average relative humidity in May is 79%.Rainfall
May is the month with the most rainfall. Rain falls for 17.5 days and accumulates 3.98" (101mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. May is the last month it regularly snows. During 0.2 snowfall days, in May, Saint Charles aggregates 0.35" (9mm) of snow. In Saint Charles, during the entire year, snow falls for 35 days and aggregates up to 15.04" (382mm) of snow.Daylight
In Saint Charles, the average length of the day in May is 14h and 31min.On the first day of the month, sunrise is at 6:11 am and sunset at 8:13 pm. On the last day of May, sunrise is at 5:44 am and sunset at 8:41 pm CDT.
Sunshine
In May, the average sunshine is 8.6h.UV index
In May, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 5 during May translates into the following directions:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Saint Charles, IA
- Average high temperature in May: 69.4°F
The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in May: 52.7°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (15.3°F).
Average pressure in May
Saint Charles, IA
- Average pressure in May: 29.93"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in May
Saint Charles, IA
- Average wind speed in May: 8.8mph
The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest month (with the lowest average wind speed) is August (7mph).
Average humidity in May
Saint Charles, IA
- Average humidity in May: 79%
The months with the highest relative humidity are January, February and June (82%).
The month with the lowest relative humidity is October (71%).
Average rainfall in May
Saint Charles, IA
- Average rainfall in May: 3.98"
The wettest month (with the highest rainfall) is May (3.98").
The driest month (with the least rainfall) is January (0.91").
Average rainfall days in May
Saint Charles, IA
- Average rainfall days in May: 17.5 days
The month with the highest number of rainy days is June (17.9 days).
The months with the least rainy days are January and February (3.8 days).
Average snowfall in May
Saint Charles, IA
- Average snowfall in May: 0.35"
The month with the highest snowfall is February (4.53").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in May
Saint Charles, IA
- Average snowfall days in May: 0.2 days
The month with the highest number of snowfall days is January (9.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Saint Charles, IA
- Average daylight in May: 14h and 30min
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 May: 8h and 36min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in May
Saint Charles, IA
- Average sunshine days in May: 11 days
The month with the most sunshine days is November (20.2 days).
The month with the least sunshine days is June (9.8 days).
Average UV index in May
Saint Charles, IA
- Average UV index in May: 5
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, October, November and December (UV index 2).
Average cloud cover in May
Saint Charles, IA
- Average cloud cover in May: 41
The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are July and September (Cloud cover 29).
Average visibility in May
Saint Charles, IA
- Average visibility in May: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).





