S
M
T
W
T
F
S
29
58°
38°
30
58°
40°
1
58°
45°
2
60°
40°
3
61°
45°
4
62°
41°
5
60°
38°
6
57°
41°
7
59°
41°
8
63°
40°
9
63°
42°
10
62°
43°
11
62°
42°
12
63°
43°
13
63°
44°
14
62°
42°
15
62°
42°
16
61°
43°
17
62°
41°
18
62°
40°
19
61°
43°
20
62°
39°
21
57°
35°
22
55°
38°
23
53°
39°
24
54°
38°
25
54°
35°
26
52°
34°
27
53°
33°
28
53°
37°
29
54°
39°
30
55°
43°
31
57°
38°
1
59°
39°
2
57°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Napa
Napa's December 2026 forecast shows daily high temperatures ranging from 52° to 63°, with overnight lows between 33° and 45°. The average high for December is 59° with an average low of 40°. 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 Napa. See also: January | February | March.
