S
M
T
W
T
F
S
30
81°
61°
31
82°
54°
1
82°
53°
2
77°
52°
3
76°
57°
4
78°
61°
5
83°
53°
6
83°
51°
7
75°
51°
8
75°
58°
9
77°
58°
10
78°
56°
11
75°
57°
12
72°
55°
13
73°
50°
14
72°
48°
15
71°
49°
16
72°
53°
17
71°
55°
18
78°
56°
19
78°
56°
20
79°
55°
21
78°
52°
22
74°
53°
23
70°
47°
24
71°
46°
25
67°
46°
26
69°
45°
27
68°
45°
28
Hist. Avg.
71°
52°
29
Hist. Avg.
70°
52°
30
Hist. Avg.
70°
51°
1
Hist. Avg.
69°
51°
2
Hist. Avg.
69°
50°
3
Hist. Avg.
68°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Downers Grove
Downers Grove's September 2026 forecast shows daily high temperatures ranging from 67° to 83°, with overnight lows between 45° and 61°. The average high for September is 75° with an average low of 53°. 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.
