S
M
T
W
T
F
S
30
61°
51°
31
56°
51°
1
57°
50°
2
57°
51°
3
56°
50°
4
56°
48°
5
57°
52°
6
59°
50°
7
57°
51°
8
59°
52°
9
62°
48°
10
56°
47°
11
56°
52°
12
57°
52°
13
58°
51°
14
63°
49°
15
62°
52°
16
62°
52°
17
62°
53°
18
61°
51°
19
63°
53°
20
64°
46°
21
62°
53°
22
63°
53°
23
61°
52°
24
62°
52°
25
59°
51°
26
61°
51°
27
60°
50°
28
57°
52°
29
58°
46°
30
58°
49°
1
60°
54°
2
64°
52°
3
65°
45°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Portland
Portland's September 2026 forecast shows daily high temperatures ranging from 56° to 65°, with overnight lows between 45° and 54°. The average high for September is 60° with an average low of 51°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Portland. See also: October | November | December.
