S
M
T
W
T
F
S
30
79°
66°
31
81°
66°
1
81°
58°
2
77°
59°
3
80°
63°
4
75°
64°
5
74°
63°
6
73°
62°
7
75°
58°
8
77°
54°
9
73°
55°
10
72°
64°
11
77°
61°
12
78°
62°
13
78°
62°
14
76°
61°
15
77°
61°
16
71°
53°
17
69°
53°
18
70°
52°
19
Hist. Avg.
74°
53°
20
Hist. Avg.
74°
53°
21
Hist. Avg.
73°
52°
22
Hist. Avg.
73°
52°
23
Hist. Avg.
73°
52°
24
Hist. Avg.
72°
51°
25
Hist. Avg.
72°
51°
26
Hist. Avg.
71°
50°
27
Hist. Avg.
71°
50°
28
Hist. Avg.
70°
49°
29
Hist. Avg.
70°
49°
30
Hist. Avg.
70°
48°
1
Hist. Avg.
69°
48°
2
Hist. Avg.
69°
48°
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 Wilmette
Wilmette's September 2026 forecast shows daily high temperatures ranging from 69° to 81°, with overnight lows between 52° and 66°. The average high for September is 76° with an average low of 60°. 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 Wilmette. See also: October | November | December.
