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