S
M
T
W
T
F
S
30
80°
61°
31
81°
61°
1
83°
60°
2
79°
57°
3
77°
57°
4
78°
58°
5
82°
58°
6
83°
60°
7
83°
61°
8
84°
61°
9
84°
60°
10
83°
59°
11
82°
60°
12
84°
61°
13
84°
61°
14
78°
49°
15
71°
51°
16
73°
56°
17
74°
53°
18
71°
48°
19
70°
46°
20
72°
47°
21
74°
50°
22
78°
53°
23
78°
45°
24
70°
45°
25
69°
53°
26
74°
53°
27
76°
52°
28
76°
45°
29
68°
43°
30
67°
42°
1
67°
47°
2
74°
48°
3
75°
50°
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 67° to 84°, with overnight lows between 42° and 61°. The average high for September is 77° with an average low of 53°. 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.
