S
M
T
W
T
F
S
29
51°
42°
30
46°
37°
1
46°
37°
2
44°
38°
3
48°
40°
4
45°
38°
5
44°
38°
6
43°
39°
7
44°
37°
8
44°
37°
9
45°
38°
10
43°
38°
11
45°
37°
12
44°
34°
13
43°
33°
14
42°
33°
15
41°
34°
16
41°
31°
17
42°
33°
18
40°
34°
19
41°
34°
20
41°
35°
21
42°
35°
22
42°
37°
23
43°
34°
24
43°
36°
25
42°
37°
26
42°
36°
27
44°
37°
28
42°
39°
29
47°
38°
30
48°
35°
31
46°
35°
1
43°
38°
2
44°
39°
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 40° to 51°, with overnight lows between 31° and 42°. The average high for December is 44° with an average low of 36°. 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.
