S
M
T
W
T
F
S
30
74°
55°
31
74°
55°
1
75°
59°
2
75°
63°
3
76°
64°
4
82°
64°
5
82°
62°
6
81°
55°
7
78°
54°
8
74°
54°
9
74°
53°
10
72°
54°
11
73°
55°
12
71°
53°
13
76°
57°
14
77°
59°
15
77°
59°
16
72°
56°
17
71°
57°
18
72°
58°
19
75°
50°
20
71°
52°
21
72°
50°
22
75°
49°
23
69°
48°
24
68°
49°
25
68°
53°
26
69°
48°
27
67°
52°
28
67°
52°
29
65°
46°
30
66°
47°
1
65°
52°
2
71°
48°
3
69°
47°
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 65° to 82°, with overnight lows between 46° and 64°. The average high for September is 73° with an average low of 54°. 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.
