S
M
T
W
T
F
S
29
52°
23°
30
47°
20°
1
36°
20°
2
37°
21°
3
41°
24°
4
45°
31°
5
48°
35°
6
50°
36°
7
52°
32°
8
51°
26°
9
47°
29°
10
42°
23°
11
41°
19°
12
35°
20°
13
36°
18°
14
35°
17°
15
33°
18°
16
35°
16°
17
33°
15°
18
31°
21°
19
34°
21°
20
38°
27°
21
41°
29°
22
45°
28°
23
45°
23°
24
40°
17°
25
35°
17°
26
32°
18°
27
33°
22°
28
41°
18°
29
40°
15°
30
32°
13°
31
30°
17°
1
32°
22°
2
40°
18°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Portland
Portland's December 2026 forecast shows daily high temperatures ranging from 30° to 52°, with overnight lows between 13° and 36°. The average high for December is 40° with an average low of 22°. 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 Portland. See also: January | February | March.
