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Hourly
7 Days
14 Days
Weekend
Monthly
Precipitation
Temperature
Wind
Temperature Unit Selection
°Celsius
°Fahrenheit
Monthly Historical Averages
Alton, IL
Content continues below
May
Average Temperature
High
25°
Feels 25
Low
14°
Feels 13
Average Precipitation
13 Days
Rain amount
130.7mm
Snow amount
0cm
Content continues below
Daily Historical Averages
May 2026
S
M
T
W
T
F
S
1
2
3
4
5
6
7
8
9
24°
10
19°
11
20°
12
25°
13
21°
14
19°
15
23°
16
26°
17
26°
18
21°
19
19°
20
24°
21
27°
22
25°
23
17°
24
25
26
27
28
29
30
31
Forecast
Saturday, May 9, 2026
Day
24°
Feels 24
Wind
19 km/h W
Gust
29 km/h
Humidity
44%
P.O.P
10%
Night
13°
Feels 11
Wind
17 km/h W
Gust
26 km/h
Humidity
94%
P.O.P
60%
Rain
1-3 mm
Historical Averages
May 9
High
Feels
Low
Feels
Precip Frequency
Total Daylight
Humidity
Historical Averages are based on data recorded from 2000 onwards.