S
M
T
W
T
F
S
30
84°
67°
31
89°
71°
1
92°
74°
2
94°
73°
3
94°
74°
4
90°
71°
5
82°
68°
6
77°
61°
7
79°
59°
8
86°
59°
9
86°
69°
10
82°
64°
11
80°
59°
12
79°
66°
13
82°
57°
14
71°
49°
15
93°
59°
16
83°
71°
17
81°
71°
18
77°
58°
19
79°
67°
20
72°
55°
21
64°
54°
22
66°
53°
23
63°
52°
24
65°
49°
25
66°
48°
26
67°
46°
27
67°
48°
28
71°
49°
29
72°
48°
30
75°
49°
1
74°
46°
2
71°
52°
3
68°
53°
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 63° to 79°, with overnight lows between 46° and 67°. The average high for September is 70° 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.
