S
M
T
W
T
F
S
29
54°
36°
30
52°
32°
1
55°
33°
2
54°
31°
3
55°
31°
4
51°
32°
5
53°
34°
6
59°
46°
7
62°
41°
8
66°
32°
9
63°
33°
10
55°
32°
11
56°
37°
12
57°
39°
13
55°
38°
14
51°
31°
15
51°
30°
16
50°
31°
17
52°
31°
18
53°
39°
19
53°
42°
20
54°
46°
21
62°
46°
22
65°
43°
23
63°
42°
24
65°
39°
25
64°
40°
26
62°
41°
27
60°
32°
28
61°
33°
29
51°
29°
30
53°
25°
31
54°
24°
1
44°
27°
2
49°
26°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Washington
Washington's December 2026 forecast shows daily high temperatures ranging from 44° to 66°, with overnight lows between 24° and 46°. The average high for December is 56° with an average low of 35°. 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 Washington. See also: January | February | March.