S
M
T
W
T
F
S
29
30°
18°
30
31°
19°
1
33°
24°
2
34°
25°
3
37°
25°
4
38°
24°
5
38°
25°
6
37°
24°
7
37°
23°
8
36°
23°
9
36°
21°
10
35°
20°
11
36°
19°
12
32°
18°
13
31°
12°
14
30°
15°
15
28°
13°
16
31°
17°
17
31°
18°
18
35°
18°
19
34°
17°
20
35°
16°
21
36°
16°
22
34°
15°
23
34°
14°
24
36°
9°
25
33°
9°
26
23°
10°
27
23°
13°
28
26°
12°
29
33°
10°
30
33°
14°
31
31°
14°
1
33°
5°
2
34°
-2°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Hayward
Hayward's December 2026 forecast shows daily high temperatures ranging from 23° to 38°, with overnight lows between -2° and 25°. The average high for December is 33° with an average low of 16°. 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 Hayward. See also: January | February | March.