S
M
T
W
T
F
S
30
83°
69°
31
86°
69°
1
95°
72°
2
96°
74°
3
88°
74°
4
93°
74°
5
81°
70°
6
77°
63°
7
78°
59°
8
85°
61°
9
79°
71°
10
77°
59°
11
80°
56°
12
85°
57°
13
71°
48°
14
71°
64°
15
83°
65°
16
71°
63°
17
75°
60°
18
70°
59°
19
72°
55°
20
68°
54°
21
69°
52°
22
70°
56°
23
71°
54°
24
70°
53°
25
70°
49°
26
75°
56°
27
74°
55°
28
73°
55°
29
71°
55°
30
71°
54°
1
72°
53°
2
72°
53°
3
71°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Vernon Hills
Vernon Hills's September 2026 forecast shows daily high temperatures ranging from 68° to 85°, with overnight lows between 48° and 65°. The average high for September is 73° with an average low of 56°. 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 Vernon Hills. See also: October | November | December.
