May weather forecastFlat Rock, IL
May
Weather in May
May, the last month of the spring in Flat Rock, is a warm month, with an average temperature varying between 57.2°F (14°C) and 73.8°F (23.2°C).Temperature
As April transitions into May, Flat Rock sees a rise in the average high-temperature, moving from a refreshing 64°F (17.8°C) to a moderately hot 73.8°F (23.2°C). Flat Rock, during May nights, observes an average temperature of 57.2°F (14°C).Humidity
In Flat Rock, the average relative humidity in May is 80%.Rainfall
In Flat Rock, during May, the rain falls for 19.8 days and regularly aggregates up to 3.98" (101mm) of precipitation. Throughout the year, in Flat Rock, there are 162.4 rainfall days, and 36.85" (936mm) of precipitation is accumulated.Snowfall
In Flat Rock, snow does not fall in May through October.Daylight
The average length of the day in May is 14h and 19min.On the first day of May, sunrise is at 5:51 am and sunset at 7:43 pm. On the last day of the month, sunrise is at 5:27 am and sunset at 8:09 pm CDT.
Sunshine
In Flat Rock, the average sunshine in May is 8.7h.UV index
The average daily maximum UV index in May is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: The UV index of 5 during May leads to these advisories:
Be vigilant - Suggestions to stave off sun damage are provided. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Experience reduced UV exposure by about half when donning a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Flat Rock, IL
- Average high temperature in May: 73.8°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (36.1°F).
- Average low temperature in May: 57.2°F
The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure in May
Flat Rock, IL
- Average pressure in May: 29.97"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
Flat Rock, IL
- Average wind speed in May: 8.1mph
The windiest months (with the highest average wind speed) are January and February (10mph).
The calmest months (with the lowest average wind speed) are July and August (5.9mph).
Average humidity in May
Flat Rock, IL
- Average humidity in May: 80%
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in May
Flat Rock, IL
- Average rainfall in May: 3.98"
The wettest month (with the highest rainfall) is April (5.2").
The driest month (with the least rainfall) is September (1.89").
Average rainfall days in May
Flat Rock, IL
- Average rainfall days in May: 19.8 days
The month with the highest number of rainy days is May (19.8 days).
The month with the least rainy days is January (8.4 days).
Average snowfall in May
Flat Rock, IL
- Average snowfall in May: 0"
The month with the highest snowfall is January (2.32").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in May
Flat Rock, IL
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (6.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in May /
Average sunshine in May
Flat Rock, IL
- Average daylight in May: 14h and 18min
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 May: 8h and 42min
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 12min).
Average sunshine days in May
Flat Rock, IL
- Average sunshine days in May: 9.7 days
The month with the most sunshine days is November (18 days).
The month with the least sunshine days is May (9.7 days).
Average UV index in May
Flat Rock, IL
- 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, November and December (UV index 2).
Average cloud cover in May
Flat Rock, IL
- Average cloud cover in May: 42
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in May
Flat Rock, IL
- Average visibility in May: 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).
