S
M
T
W
T
F
S
30
85°
51°
31
84°
47°
1
83°
46°
2
84°
47°
3
85°
50°
4
85°
49°
5
84°
49°
6
82°
45°
7
84°
48°
8
90°
52°
9
90°
52°
10
91°
53°
11
91°
53°
12
90°
52°
13
90°
52°
14
83°
45°
15
81°
48°
16
83°
51°
17
89°
50°
18
90°
51°
19
89°
50°
20
88°
50°
21
88°
49°
22
89°
50°
23
86°
49°
24
83°
49°
25
85°
48°
26
87°
49°
27
87°
48°
28
79°
45°
29
79°
48°
30
80°
45°
1
78°
40°
2
75°
39°
3
75°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Cottage Grove
Cottage Grove's September 2026 forecast shows daily high temperatures ranging from 75° to 91°, with overnight lows between 39° and 53°. The average high for September is 85° 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 Cottage Grove. See also: October | November | December.
