S
M
T
W
T
F
S
29
40°
32°
30
39°
32°
1
41°
30°
2
40°
33°
3
39°
35°
4
41°
34°
5
40°
32°
6
38°
31°
7
38°
29°
8
39°
29°
9
37°
35°
10
39°
38°
11
45°
36°
12
44°
33°
13
43°
30°
14
40°
34°
15
40°
34°
16
44°
35°
17
40°
37°
18
44°
37°
19
45°
35°
20
44°
31°
21
42°
27°
22
37°
33°
23
39°
30°
24
42°
28°
25
37°
29°
26
37°
32°
27
42°
34°
28
41°
31°
29
Hist. Avg.
44°
36°
30
Hist. Avg.
44°
36°
31
Hist. Avg.
44°
36°
1
Hist. Avg.
45°
36°
2
Hist. Avg.
45°
36°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
December Weather in Index
Index's December 2026 forecast shows daily high temperatures ranging from 37° to 45°, with overnight lows between 27° and 38°. The average high for December is 41° with an average low of 33°. 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 Index. See also: January | February | March.