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