S
M
T
W
T
F
S
29
45°
35°
30
46°
36°
1
55°
32°
2
51°
36°
3
47°
33°
4
57°
28°
5
55°
28°
6
42°
29°
7
43°
30°
8
44°
28°
9
43°
26°
10
41°
25°
11
38°
27°
12
39°
28°
13
40°
27°
14
40°
28°
15
39°
30°
16
40°
31°
17
41°
29°
18
40°
37°
19
43°
35°
20
45°
31°
21
43°
28°
22
39°
26°
23
39°
26°
24
38°
30°
25
38°
28°
26
39°
29°
27
37°
29°
28
38°
28°
29
36°
24°
30
38°
24°
31
40°
20°
1
Hist. Avg.
41°
28°
2
Hist. Avg.
41°
28°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Oceanside
Oceanside's December 2026 forecast shows daily high temperatures ranging from 36° to 57°, with overnight lows between 20° and 37°. The average high for December is 42° with an average low of 29°. 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 Oceanside. See also: January | February | March.
