S
M
T
W
T
F
S
30
77°
66°
31
86°
71°
1
85°
74°
2
96°
73°
3
95°
70°
4
80°
68°
5
76°
65°
6
79°
56°
7
79°
57°
8
84°
57°
9
83°
67°
10
82°
60°
11
79°
56°
12
81°
61°
13
83°
56°
14
72°
48°
15
87°
55°
16
76°
68°
17
77°
67°
18
75°
62°
19
68°
59°
20
65°
57°
21
63°
53°
22
62°
52°
23
66°
57°
24
69°
49°
25
69°
45°
26
73°
45°
27
76°
47°
28
76°
51°
29
77°
57°
30
72°
62°
1
79°
60°
2
63°
47°
3
65°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Grand Rapids
Grand Rapids's September 2026 forecast shows daily high temperatures ranging from 63° to 79°, with overnight lows between 47° and 62°. The average high for September is 71° with an average low of 55°. 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 Grand Rapids. See also: October | November | December.
