S
M
T
W
T
F
S
30
79°
65°
31
77°
64°
1
74°
68°
2
74°
64°
3
76°
60°
4
74°
65°
5
73°
67°
6
81°
68°
7
82°
69°
8
81°
67°
9
81°
64°
10
73°
67°
11
72°
66°
12
79°
58°
13
Hist. Avg.
78°
60°
14
Hist. Avg.
77°
60°
15
Hist. Avg.
77°
59°
16
Hist. Avg.
76°
59°
17
Hist. Avg.
76°
58°
18
Hist. Avg.
76°
58°
19
Hist. Avg.
75°
58°
20
Hist. Avg.
75°
57°
21
Hist. Avg.
75°
57°
22
Hist. Avg.
74°
56°
23
Hist. Avg.
74°
56°
24
Hist. Avg.
73°
56°
25
Hist. Avg.
73°
55°
26
Hist. Avg.
73°
55°
27
Hist. Avg.
72°
54°
28
Hist. Avg.
72°
54°
29
Hist. Avg.
71°
53°
30
Hist. Avg.
71°
53°
1
Hist. Avg.
70°
53°
2
Hist. Avg.
70°
52°
3
Hist. Avg.
70°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Chicago
Chicago's September 2026 forecast shows daily high temperatures ranging from 72° to 82°, with overnight lows between 58° and 69°. The average high for September is 77° with an average low of 65°. 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 Chicago. See also: October | November | December.
