S
M
T
W
T
F
S
30
88°
68°
31
88°
66°
1
86°
68°
2
87°
66°
3
90°
69°
4
91°
69°
5
91°
70°
6
90°
66°
7
87°
68°
8
88°
68°
9
89°
68°
10
85°
67°
11
87°
66°
12
88°
68°
13
88°
66°
14
87°
66°
15
87°
67°
16
88°
67°
17
87°
66°
18
87°
65°
19
85°
65°
20
86°
64°
21
85°
64°
22
84°
65°
23
85°
63°
24
85°
62°
25
84°
61°
26
85°
60°
27
84°
62°
28
84°
62°
29
83°
61°
30
83°
61°
1
82°
59°
2
83°
61°
3
78°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Gurnee
Gurnee's September 2026 forecast shows daily high temperatures ranging from 78° to 91°, with overnight lows between 58° and 70°. The average high for September is 86° 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 Gurnee. See also: October | November | December.
