S
M
T
W
T
F
S
29
33°
24°
30
38°
26°
1
36°
30°
2
38°
29°
3
41°
29°
4
40°
30°
5
40°
29°
6
41°
29°
7
39°
28°
8
35°
28°
9
38°
26°
10
35°
24°
11
41°
20°
12
35°
16°
13
30°
9°
14
28°
12°
15
27°
10°
16
32°
20°
17
32°
23°
18
33°
23°
19
34°
20°
20
34°
22°
21
32°
22°
22
33°
23°
23
37°
19°
24
37°
11°
25
34°
11°
26
24°
13°
27
28°
19°
28
31°
20°
29
37°
21°
30
36°
24°
31
40°
25°
1
39°
13°
2
40°
8°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Fairfax
Fairfax's December 2026 forecast shows daily high temperatures ranging from 24° to 41°, with overnight lows between 8° and 30°. The average high for December is 35° with an average low of 21°. 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 Fairfax. See also: January | February | March.
