S
M
T
W
T
F
S
29
40°
26°
30
40°
26°
1
41°
29°
2
40°
34°
3
51°
27°
4
54°
23°
5
37°
28°
6
37°
28°
7
42°
29°
8
49°
31°
9
37°
22°
10
35°
20°
11
Hist. Avg.
42°
28°
12
Hist. Avg.
41°
28°
13
Hist. Avg.
41°
27°
14
Hist. Avg.
41°
27°
15
Hist. Avg.
41°
27°
16
Hist. Avg.
40°
27°
17
Hist. Avg.
40°
26°
18
Hist. Avg.
40°
26°
19
Hist. Avg.
40°
26°
20
Hist. Avg.
39°
26°
21
Hist. Avg.
39°
26°
22
Hist. Avg.
39°
25°
23
Hist. Avg.
39°
25°
24
Hist. Avg.
38°
25°
25
Hist. Avg.
38°
25°
26
Hist. Avg.
38°
24°
27
Hist. Avg.
38°
24°
28
Hist. Avg.
38°
24°
29
Hist. Avg.
38°
24°
30
Hist. Avg.
38°
24°
31
Hist. Avg.
37°
23°
1
Hist. Avg.
37°
23°
2
Hist. Avg.
37°
23°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
December Weather in Heidelberg
Heidelberg's December 2026 forecast shows daily high temperatures ranging from 35° to 54°, with overnight lows between 20° and 34°. The average high for December is 42° with an average low of 27°. 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 Heidelberg. See also: January | February | March.
