S
M
T
W
T
F
S
29
49°
24°
30
41°
23°
1
50°
24°
2
49°
23°
3
39°
22°
4
40°
22°
5
44°
22°
6
43°
22°
7
45°
23°
8
37°
22°
9
36°
20°
10
35°
21°
11
35°
21°
12
46°
20°
13
45°
22°
14
47°
22°
15
46°
20°
16
47°
22°
17
46°
22°
18
44°
21°
19
40°
19°
20
41°
20°
21
44°
21°
22
45°
20°
23
35°
20°
24
46°
21°
25
35°
15°
26
39°
16°
27
39°
7°
28
38°
9°
29
35°
6°
30
34°
4°
31
34°
6°
1
33°
12°
2
35°
7°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Sidney
Sidney's December 2026 forecast shows daily high temperatures ranging from 33° to 50°, with overnight lows between 4° and 24°. The average high for December is 41° with an average low of 18°. 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 Sidney. See also: January | February | March.
