S
M
T
W
T
F
S
29
66°
45°
30
63°
46°
1
65°
42°
2
51°
34°
3
50°
30°
4
53°
36°
5
59°
40°
6
51°
34°
7
49°
32°
8
48°
29°
9
48°
31°
10
46°
28°
11
47°
29°
12
50°
32°
13
54°
32°
14
50°
32°
15
50°
38°
16
52°
36°
17
51°
33°
18
55°
31°
19
48°
27°
20
47°
27°
21
46°
28°
22
48°
29°
23
48°
31°
24
45°
28°
25
45°
27°
26
46°
28°
27
47°
27°
28
47°
27°
29
48°
32°
30
47°
29°
31
46°
27°
1
45°
25°
2
44°
26°
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 44° to 66°, with overnight lows between 25° and 46°. The average high for December is 50° with an average low of 32°. 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.
