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Current
Hourly
7 Days
14 Days
Weekend
Monthly
Precipitation
Temperature
Wind
Temperature Unit Selection
°Celsius
°Fahrenheit
Monthly Historical Averages
Decatur, IL
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Daily Historical Averages
September 2026
S
M
T
W
T
F
S
1
2
35°
3
35°
4
34°
5
32°
6
31°
7
31°
8
31°
9
34°
10
29°
11
29°
12
28°
13
28°
14
28°
15
28°
16
29°
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Forecast
Wednesday, September 2, 2026
Day
35°
Feels 38
Wind
20 km/h SW
Gust
30 km/h
Humidity
38%
P.O.P
30%
Night
25°
Feels 25
Wind
13 km/h SW
Gust
20 km/h
Humidity
70%
P.O.P
20%
Historical Averages
Sep 2
High
Feels
Low
Feels
Precip Frequency
Total Daylight
Humidity
Historical Averages are based on data recorded from 2000 onwards.
September
Average Temperature
High
27°
Feels 27
Low
15°
Feels 14
Average Precipitation
8 Days
Rain amount
58.2mm
Snow amount
0cm