S
M
T
W
T
F
S
30
79°
42°
31
86°
46°
1
72°
54°
2
62°
52°
3
64°
49°
4
67°
49°
5
71°
50°
6
75°
53°
7
72°
53°
8
76°
52°
9
77°
51°
10
78°
50°
11
79°
53°
12
76°
52°
13
77°
50°
14
81°
48°
15
71°
50°
16
70°
50°
17
70°
44°
18
71°
45°
19
69°
50°
20
68°
48°
21
68°
43°
22
69°
43°
23
68°
45°
24
67°
44°
25
66°
46°
26
67°
43°
27
68°
50°
28
65°
49°
29
67°
48°
30
66°
49°
1
65°
46°
2
65°
41°
3
66°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Corvallis
Corvallis's September 2026 forecast shows daily high temperatures ranging from 62° to 81°, with overnight lows between 41° and 54°. The average high for September is 70° with an average low of 48°. 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 Corvallis. See also: October | November | December.
