S
M
T
W
T
F
S
29
50°
29°
30
47°
30°
1
49°
30°
2
49°
29°
3
38°
28°
4
37°
25°
5
41°
26°
6
37°
24°
7
39°
26°
8
37°
18°
9
31°
17°
10
31°
25°
11
39°
26°
12
41°
26°
13
38°
27°
14
45°
26°
15
44°
25°
16
44°
26°
17
45°
26°
18
43°
25°
19
38°
23°
20
33°
23°
21
40°
18°
22
41°
12°
23
35°
12°
24
28°
8°
25
36°
14°
26
27°
21°
27
41°
21°
28
43°
20°
29
42°
11°
30
36°
9°
31
30°
5°
1
26°
6°
2
23°
15°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Ithaca
Ithaca's December 2026 forecast shows daily high temperatures ranging from 23° to 50°, with overnight lows between 5° and 30°. The average high for December is 38° with an average low of 21°. 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 Ithaca. See also: January | February | March.
