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