S
M
T
W
T
F
S
30
75°
45°
31
75°
49°
1
74°
47°
2
74°
45°
3
75°
47°
4
75°
47°
5
73°
48°
6
73°
43°
7
74°
45°
8
81°
48°
9
82°
51°
10
82°
52°
11
81°
51°
12
83°
52°
13
82°
51°
14
80°
42°
15
75°
46°
16
75°
50°
17
80°
51°
18
81°
48°
19
80°
47°
20
80°
49°
21
78°
50°
22
79°
50°
23
79°
47°
24
77°
49°
25
77°
50°
26
78°
50°
27
78°
48°
28
70°
46°
29
68°
48°
30
71°
47°
1
68°
45°
2
64°
41°
3
64°
44°
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 64° to 83°, with overnight lows between 41° and 52°. The average high for September is 76° 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.
