S
M
T
W
T
F
S
29
36°
20°
30
36°
25°
1
37°
18°
2
36°
16°
3
33°
23°
4
33°
27°
5
37°
29°
6
41°
27°
7
42°
24°
8
40°
21°
9
35°
12°
10
34°
15°
11
31°
20°
12
32°
12°
13
32°
9°
14
26°
14°
15
28°
18°
16
30°
16°
17
35°
22°
18
35°
24°
19
36°
25°
20
40°
20°
21
41°
19°
22
34°
20°
23
36°
20°
24
35°
16°
25
35°
14°
26
30°
6°
27
26°
3°
28
24°
10°
29
21°
-2°
30
26°
0°
31
18°
1°
1
18°
14°
2
22°
8°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Sumner
Sumner's December 2026 forecast shows daily high temperatures ranging from 18° to 42°, with overnight lows between -2° and 29°. The average high for December is 32° with an average low of 16°. 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 Sumner. See also: January | February | March.
