S
M
T
W
T
F
S
29
46°
31°
30
43°
30°
1
36°
29°
2
34°
22°
3
34°
28°
4
38°
28°
5
37°
27°
6
34°
20°
7
28°
13°
8
27°
14°
9
29°
15°
10
34°
24°
11
36°
24°
12
39°
26°
13
35°
26°
14
28°
25°
15
37°
21°
16
36°
22°
17
34°
21°
18
33°
19°
19
32°
15°
20
29°
9°
21
27°
20°
22
32°
19°
23
34°
20°
24
32°
15°
25
34°
12°
26
30°
20°
27
28°
20°
28
33°
16°
29
30°
12°
30
29°
15°
31
28°
6°
1
30°
2°
2
20°
6°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Decorah
Decorah's December 2026 forecast shows daily high temperatures ranging from 20° to 46°, with overnight lows between 2° and 31°. The average high for December is 33° with an average low of 19°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how December weather will actually feel in Decorah. See also: January | February | March.
