S
M
T
W
T
F
S
29
39°
23°
30
37°
21°
1
35°
17°
2
32°
21°
3
34°
22°
4
35°
21°
5
35°
22°
6
34°
20°
7
34°
18°
8
33°
16°
9
30°
17°
10
29°
16°
11
30°
16°
12
28°
10°
13
29°
5°
14
22°
10°
15
18°
11°
16
24°
-1°
17
29°
-4°
18
29°
-1°
19
13°
8°
20
19°
4°
21
21°
11°
22
19°
12°
23
27°
13°
24
26°
14°
25
29°
12°
26
18°
12°
27
16°
6°
28
24°
13°
29
Hist. Avg.
21°
2°
30
Hist. Avg.
21°
2°
31
Hist. Avg.
21°
1°
1
Hist. Avg.
21°
1°
2
Hist. Avg.
21°
1°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
December Weather in Mercer
Mercer's December 2026 forecast shows daily high temperatures ranging from 13° to 39°, with overnight lows between -4° and 23°. The average high for December is 28° 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 Mercer. See also: January | February | March.
