S
M
T
W
T
F
S
30
79°
56°
31
76°
53°
1
72°
53°
2
66°
60°
3
66°
61°
4
80°
63°
5
75°
58°
6
74°
53°
7
82°
50°
8
79°
57°
9
67°
51°
10
83°
59°
11
72°
49°
12
68°
60°
13
69°
61°
14
75°
51°
15
69°
57°
16
77°
60°
17
70°
57°
18
71°
54°
19
69°
49°
20
69°
49°
21
66°
51°
22
67°
50°
23
68°
49°
24
69°
53°
25
62°
45°
26
63°
46°
27
61°
52°
28
62°
52°
29
62°
50°
30
61°
50°
1
61°
52°
2
63°
51°
3
67°
51°
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 61° to 83°, with overnight lows between 45° and 61°. The average high for September is 68° with an average low of 52°. 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.
