S
M
T
W
T
F
S
30
75°
59°
31
75°
58°
1
76°
61°
2
77°
62°
3
76°
62°
4
83°
63°
5
83°
62°
6
80°
61°
7
79°
60°
8
75°
59°
9
76°
60°
10
74°
60°
11
75°
59°
12
76°
58°
13
78°
59°
14
79°
59°
15
80°
58°
16
78°
58°
17
77°
57°
18
77°
58°
19
74°
57°
20
77°
58°
21
80°
55°
22
79°
50°
23
79°
43°
24
70°
44°
25
73°
50°
26
77°
47°
27
72°
54°
28
76°
56°
29
78°
56°
30
77°
50°
1
78°
44°
2
68°
51°
3
66°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Downers Grove
Downers Grove's September 2026 forecast shows daily high temperatures ranging from 66° to 83°, with overnight lows between 43° and 63°. The average high for September is 76° with an average low of 56°. 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 Downers Grove. See also: October | November | December.
