S
M
T
W
T
F
S
30
82°
57°
31
78°
55°
1
76°
58°
2
75°
57°
3
77°
57°
4
76°
56°
5
75°
56°
6
74°
60°
7
74°
56°
8
75°
56°
9
76°
55°
10
75°
55°
11
74°
54°
12
74°
54°
13
73°
56°
14
74°
56°
15
77°
59°
16
80°
58°
17
81°
59°
18
80°
56°
19
79°
57°
20
Hist. Avg.
74°
53°
21
Hist. Avg.
74°
52°
22
Hist. Avg.
73°
52°
23
Hist. Avg.
73°
51°
24
Hist. Avg.
72°
51°
25
Hist. Avg.
72°
50°
26
Hist. Avg.
72°
50°
27
Hist. Avg.
71°
50°
28
Hist. Avg.
71°
49°
29
Hist. Avg.
70°
49°
30
Hist. Avg.
70°
48°
1
Hist. Avg.
69°
48°
2
Hist. Avg.
69°
47°
3
Hist. Avg.
68°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Joliet
Joliet's September 2026 forecast shows daily high temperatures ranging from 73° to 82°, with overnight lows between 54° and 60°. The average high for September is 76° with an average low of 57°. 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 Joliet. See also: October | November | December.
