This page presents a long range weather forecast for Illinois in May as well as other months. You can quickly get a brief overview of the weather to expect in May on a daily basis.
The Illinois extended forecast data provided is based on the average values of previous years.
Long range weather forecast
Select a month and click on a day for more information:
Wednesday
May 1
21° / 14°
Thursday
May 2
20° / 11°
Friday
May 3
16° / 10°
Saturday
May 4
20° / 9°
Sunday
May 5
14° / 10°
Monday
May 6
15° / 9°
Tuesday
May 7
25° / 15°
Wednesday
May 8
24° / 15°
Thursday
May 9
22° / 13°
Friday
May 10
18° / 10°
Saturday
May 11
15° / 8°
Sunday
May 12
18° / 10°
Monday
May 13
18° / 13°
Tuesday
May 14
11° / 10°
Wednesday
May 15
16° / 12°
Thursday
May 16
18° / 11°
Friday
May 17
15° / 10°
Saturday
May 18
19° / 10°
Sunday
May 19
20° / 11°
Monday
May 20
17° / 12°
Tuesday
May 21
17° / 11°
Wednesday
May 22
20° / 13°
Thursday
May 23
21° / 15°
Friday
May 24
20° / 13°
Saturday
May 25
23° / 16°
Sunday
May 26
20° / 15°
Monday
May 27
19° / 13°
Tuesday
May 28
18° / 11°
Wednesday
May 29
19° / 12°
Thursday
May 30
21° / 14°
Friday
May 31
22° / 16°
Illinois 30 days weather forecast
Check out our estimated 30 days weather forecast for Illinois, this data is based on the average weather in Illinois in the last few years.
For a more accurate and detailed forecast, check out the 14 day weather for Illinois next to the desired date.