S
M
T
W
T
F
S
30
85°
62°
31
86°
62°
1
87°
61°
2
84°
57°
3
81°
57°
4
83°
58°
5
84°
57°
6
85°
60°
7
86°
61°
8
87°
61°
9
87°
62°
10
86°
61°
11
85°
60°
12
86°
61°
13
87°
62°
14
84°
54°
15
75°
54°
16
76°
54°
17
79°
55°
18
74°
52°
19
73°
47°
20
74°
49°
21
81°
50°
22
82°
50°
23
82°
49°
24
76°
46°
25
73°
49°
26
78°
53°
27
78°
54°
28
79°
49°
29
71°
44°
30
70°
45°
1
71°
46°
2
78°
47°
3
78°
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 70° to 87°, with overnight lows between 44° and 62°. The average high for September is 80° 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.
