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Monthly
Forecasts
Current
Hourly
7 Days
14 Days
Monthly
°C
Temperature Unit Selection
°Celsius
°Fahrenheit
Monthly Historical Averages
Decatur, IL
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December
Average Temperature
High
4°
Feels 1
Low
-3°
Feels -8
Average Precipitation
8 Days
Rain amount
40.3mm
Snow amount
3.2cm
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Daily Historical Averages
December 2025
S
M
T
W
T
F
S
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
13°
25
12°
26
17°
27
14°
28
11°
29
-4°
30
0°
31
6°
Forecast
Wednesday, December 24, 2025
Day
13°
Feels 11
Wind
17 km/h E
Gust
26 km/h
Humidity
75%
P.O.P
40%
Rain
<1 mm
Night
9°
Feels 7
Wind
15 km/h S
Gust
22 km/h
Humidity
99%
P.O.P
40%
Rain
<1 mm
Historical Averages
Dec 24
High
Feels
Low
Feels
Precip Frequency
Total Daylight
Humidity
Historical Averages are based on data recorded from 2000 onwards.