S
M
T
W
T
F
S
29
39°
32°
30
40°
30°
1
40°
32°
2
41°
26°
3
39°
25°
4
36°
31°
5
38°
36°
6
43°
41°
7
49°
34°
8
52°
31°
9
50°
29°
10
37°
28°
11
38°
26°
12
39°
28°
13
37°
30°
14
37°
27°
15
35°
24°
16
34°
26°
17
34°
29°
18
35°
30°
19
36°
34°
20
42°
34°
21
49°
27°
22
48°
28°
23
37°
34°
24
45°
32°
25
47°
31°
26
42°
31°
27
38°
20°
28
39°
19°
29
30°
16°
30
32°
13°
31
31°
15°
1
25°
17°
2
29°
22°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Castalia
Castalia's December 2026 forecast shows daily high temperatures ranging from 25° to 52°, with overnight lows between 13° and 41°. The average high for December is 39° with an average low of 28°. 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 Castalia. See also: January | February | March.
