S
M
T
W
T
F
S
29
33°
9°
30
24°
10°
1
21°
15°
2
30°
16°
3
31°
16°
4
31°
15°
5
30°
14°
6
29°
13°
7
28°
13°
8
28°
6°
9
27°
2°
10
20°
3°
11
17°
3°
12
17°
5°
13
19°
6°
14
16°
4°
15
20°
-3°
16
16°
-5°
17
10°
8°
18
20°
8°
19
24°
11°
20
26°
6°
21
26°
-1°
22
24°
-3°
23
11°
-2°
24
9°
2°
25
13°
5°
26
18°
6°
27
24°
-2°
28
23°
-7°
29
16°
2°
30
14°
4°
31
20°
-3°
1
20°
-10°
2
18°
0°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Roseau
Roseau's December 2026 forecast shows daily high temperatures ranging from 9° to 33°, with overnight lows between -10° and 16°. The average high for December is 22° with an average low of 5°. 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 Roseau. See also: January | February | March.