May weather forecastRomeoville, IL
May
Weather in May
The last month of the spring, May, is an agreeable month in Romeoville, Illinois, with an average temperature varying between 52.3°F (11.3°C) and 69.4°F (20.8°C).Temperature
With the onset of May, Romeoville experiences a temperature shift, with the average high-temperature moving from a refreshing 57°F (13.9°C) in April to an agreeable 69.4°F (20.8°C). Romeoville's temperature lowers to a mean of 52.3°F (11.3°C) during the nights in May.Humidity
In Romeoville, the average relative humidity in May is 76%.Rainfall
May is the month with the most rainfall. Rain falls for 16.4 days and accumulates 2.83" (72mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. May is the last month it regularly snows. During 0.1 snowfall days, in May, Romeoville aggregates 0.04" (1mm) of snow. In Romeoville, during the entire year, snow falls for 44.4 days and aggregates up to 11.93" (303mm) of snow.Daylight
The average length of the day in May is 14h and 33min.On the first day of May, sunrise is at 5:47 am and sunset at 7:50 pm. On the last day of the month, sunrise is at 5:20 am and sunset at 8:19 pm CDT.
Sunshine
In Romeoville, Illinois, the average sunshine in May is 8.7h.UV index
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 unprotected exposure to Sun's UV rays for the ordinary person.Note: A typical high UV index of 5 in May suggests the following recommendations:
Make use of precautions - Shielding skin and eyes from injury is a requirement. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Remember this! The UV radiation of the Sun can be nearly doubled by the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Romeoville, IL
- Average high temperature in May: 69.4°F
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in May: 52.3°F
The month with the highest average low temperature is July (65.7°F).
The coldest month (with the lowest average low temperature) is January (17.1°F).
Average pressure in May
Romeoville, IL
- Average pressure in May: 29.96"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in May
Romeoville, IL
- Average wind speed in May: 8.1mph
The windiest month (with the highest average wind speed) is January (9.7mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in May
Romeoville, IL
- Average humidity in May: 76%
The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (73%).
Average rainfall in May
Romeoville, IL
- Average rainfall in May: 2.83"
The wettest month (with the highest rainfall) is May (2.83").
The driest month (with the least rainfall) is December (1.06").
Average rainfall days in May
Romeoville, IL
- Average rainfall days in May: 16.4 days
The month with the highest number of rainy days is July (18.1 days).
The month with the least rainy days is February (4.9 days).
Average snowfall in May
Romeoville, IL
- Average snowfall in May: 0.04"
The month with the highest snowfall is January (3.11").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in May
Romeoville, IL
- Average snowfall days in May: 0.1 days
The month with the highest number of snowfall days is January (12.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Romeoville, IL
- Average daylight in May: 14h and 36min
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 12min).
- Average sunshine in May: 8h and 42min
The months with the most sunshine are July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in May
Romeoville, IL
- Average sunshine days in May: 11.7 days
The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is July (9.3 days).
Average UV index in May
Romeoville, 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
Romeoville, IL
- Average cloud cover in May: 42
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in May
Romeoville, IL
- Average visibility in May: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
