S
M
T
W
T
F
S
29
57°
38°
30
56°
37°
1
57°
28°
2
42°
24°
3
45°
30°
4
53°
36°
5
49°
35°
6
41°
30°
7
41°
24°
8
39°
21°
9
39°
23°
10
41°
28°
11
45°
28°
12
50°
29°
13
47°
27°
14
42°
25°
15
43°
27°
16
41°
29°
17
40°
26°
18
41°
21°
19
39°
19°
20
37°
17°
21
35°
21°
22
39°
27°
23
42°
23°
24
39°
20°
25
37°
18°
26
37°
21°
27
39°
20°
28
39°
19°
29
38°
24°
30
38°
20°
31
39°
18°
1
37°
14°
2
35°
17°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Mountain View
Mountain View's December 2026 forecast shows daily high temperatures ranging from 35° to 57°, with overnight lows between 14° and 38°. The average high for December is 42° with an average low of 25°. 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 Mountain View. See also: January | February | March.