Contents
- Weather in May
- Frequently asked questions
- Average temperature in May
- Average pressure in May
- Average wind speed in May
- Average humidity in May
- Average rainfall in May
- Average rainfall days in May
- Average snowfall in May
- Average snowfall days in May
- Average daylight in May
- Average sunshine in May
- Average sunshine days in May
- Average UV index in May
- Average cloud cover in May
- Average visibility in May
Weather in May
Temperature
With the onset of May, Sullivan's average high-temperature experiences a rise, moving from April's refreshing 62.2°F (16.8°C) to a pleasant 72.9°F (22.7°C). The average temperature during May nights is registered at a refreshing 56.7°F (13.7°C).Humidity
The average relative humidity in May in Sullivan is 78%.Rainfall
In Sullivan, in May, it is raining for 16.3 days, with typically 1.77" (45mm) of accumulated precipitation. Throughout the year, in Sullivan, there are 130.9 rainfall days, and 15.43" (392mm) of precipitation is accumulated.Snowfall
In Sullivan, snow does not fall in May through October.Daylight
The average length of the day in May in Sullivan is 14h and 22min.On the first day of the month, sunrise is at 5:54 am and sunset at 7:48 pm. On the last day of May, in Sullivan, sunrise is at 5:28 am and sunset at 8:15 pm CDT.
Sunshine
In Sullivan, the average sunshine in May is 9.1h.UV index
In May, the average daily maximum UV index in Sullivan, Illinois, is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for the average person.Note: The maximum daily UV index of 5 in May interprets into the following recommendations:
Exercise prevention - Precautions against solar damage are endorsed. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Sullivan in May?
What is the average humidity in May in Sullivan?
How many days does it rain in May in Sullivan?
When it does not snow in Sullivan?
Does it snow in Sullivan in May?
What is the average length of the day in May in Sullivan?
When is the sunrise / sunset in May in Sullivan?
How many hours of sunshine does Sullivan have in May?
What is the UV index reading in May in Sullivan?
Average temperature in May
Sullivan, IL
- Average high temperature in May: 72.9°F
The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (33.6°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 (21.6°F).
Average pressure in May
Sullivan, 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
Sullivan, IL
- Average wind speed in May: 8.7mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.3mph).
Average humidity in May
Sullivan, IL
- Average humidity in May: 78%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (70%).
Average rainfall in May
Sullivan, IL
- Average rainfall in May: 1.77"
The wettest month (with the highest rainfall) is June (1.85").
The driest month (with the least rainfall) is February (0.71").
Average rainfall days in May
Sullivan, IL
- Average rainfall days in May: 16.3 days
The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is February (5.9 days).
Average snowfall in May
Sullivan, IL
- Average snowfall in May: 0"
The month with the highest snowfall is January (1.54").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in May
Sullivan, IL
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (6.4 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
Sullivan, IL
- Average daylight in May: 14h 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 24min).
- Average sunshine in May: 9h and 1min
The month with the most sunshine is June (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in May
Sullivan, IL
- Average sunshine days in May: 12.3 days
The month with the most sunshine days is October (20.5 days).
The month with the least sunshine days is May (12.3 days).
Average UV index in May
Sullivan, 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
Sullivan, IL
- Average cloud cover in May: 39
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is June (Cloud cover 30).
Average visibility in May
Sullivan, 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).
Sullivan, Illinois, USA
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