S
M
T
W
T
F
S
29
46°
34°
30
45°
32°
1
43°
32°
2
44°
33°
3
44°
35°
4
45°
32°
5
43°
34°
6
44°
33°
7
42°
35°
8
45°
41°
9
46°
41°
10
49°
40°
11
49°
42°
12
48°
40°
13
49°
41°
14
48°
42°
15
49°
41°
16
50°
40°
17
50°
39°
18
46°
35°
19
44°
34°
20
46°
36°
21
46°
33°
22
45°
38°
23
46°
39°
24
44°
38°
25
48°
39°
26
46°
38°
27
44°
36°
28
45°
35°
29
42°
33°
30
42°
32°
31
Hist. Avg.
44°
32°
1
Hist. Avg.
44°
32°
2
Hist. Avg.
44°
32°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
December Weather in Happy Valley
Happy Valley's December 2026 forecast shows daily high temperatures ranging from 42° to 50°, with overnight lows between 32° and 42°. The average high for December is 46° with an average low of 37°. 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 Happy Valley. See also: January | February | March.
