S
M
T
W
T
F
S
29
38°
14°
30
29°
9°
1
27°
8°
2
29°
19°
3
37°
19°
4
29°
16°
5
28°
13°
6
27°
7°
7
25°
6°
8
27°
8°
9
35°
10°
10
37°
8°
11
38°
13°
12
38°
14°
13
39°
12°
14
30°
16°
15
28°
18°
16
32°
11°
17
29°
7°
18
27°
7°
19
28°
11°
20
28°
15°
21
30°
10°
22
29°
9°
23
27°
16°
24
29°
11°
25
28°
18°
26
29°
16°
27
35°
4°
28
30°
6°
29
26°
8°
30
28°
4°
31
26°
12°
1
27°
15°
2
30°
14°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Rock River
Rock River's December 2026 forecast shows daily high temperatures ranging from 25° to 39°, with overnight lows between 4° and 19°. The average high for December is 30° with an average low of 12°. 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 Rock River. See also: January | February | March.
