S
M
T
W
T
F
S
29
32°
22°
30
29°
20°
1
29°
19°
2
28°
18°
3
31°
24°
4
34°
22°
5
35°
24°
6
35°
22°
7
32°
24°
8
32°
24°
9
33°
20°
10
25°
15°
11
35°
17°
12
35°
19°
13
29°
20°
14
28°
13°
15
31°
6°
16
25°
13°
17
25°
18°
18
32°
10°
19
32°
10°
20
22°
16°
21
25°
18°
22
31°
19°
23
31°
19°
24
32°
18°
25
33°
12°
26
32°
8°
27
25°
4°
28
18°
10°
29
19°
16°
30
30°
16°
31
30°
15°
1
30°
19°
2
33°
14°
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 18° to 35°, with overnight lows between 4° and 24°. The average high for December is 30° with an average low of 17°. 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.
