Monthly Historical AveragesUnion, IL
Average Temperature
High
21°
Feels 21
Low
10°
Feels 8
Average Precipitation
13 Days
78.4mm
0cm
Content continues below
Daily Historical Averages
S
M
T
W
T
F
S
ForecastFriday, May 15, 2026
Day
23°Feels 23
Wind
30 km/h S
Gust
45 km/h
Humidity
48%
P.O.P
30%
Night
15°Feels 13
Wind
28 km/h S
Gust
42 km/h
Humidity
94%
P.O.P
60%
Rain
5-10 mm
Historical AveragesMay 15
High
Feels
Low
Feels
Precip Frequency
Total Daylight
Humidity