S
M
T
W
T
F
S
29
46°
25°
30
52°
38°
1
48°
38°
2
47°
37°
3
47°
38°
4
48°
38°
5
51°
36°
6
54°
37°
7
54°
34°
8
50°
27°
9
44°
24°
10
44°
32°
11
58°
24°
12
60°
21°
13
52°
20°
14
41°
25°
15
46°
21°
16
43°
27°
17
49°
33°
18
50°
34°
19
56°
34°
20
56°
33°
21
55°
33°
22
54°
36°
23
58°
23°
24
58°
18°
25
54°
16°
26
37°
19°
27
43°
27°
28
46°
34°
29
54°
35°
30
56°
37°
31
57°
34°
1
59°
25°
2
59°
20°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Summit
Summit's December 2026 forecast shows daily high temperatures ranging from 37° to 60°, with overnight lows between 16° and 38°. The average high for December is 51° with an average low of 30°. 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 Summit. See also: January | February | March.
