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