S
M
T
W
T
F
S
30
79°
63°
31
77°
64°
1
81°
68°
2
84°
70°
3
84°
64°
4
81°
63°
5
73°
63°
6
75°
57°
7
73°
54°
8
77°
59°
9
79°
63°
10
72°
66°
11
75°
59°
12
79°
63°
13
75°
63°
14
64°
52°
15
75°
63°
16
82°
67°
17
77°
63°
18
72°
55°
19
73°
62°
20
69°
60°
21
70°
61°
22
70°
59°
23
67°
56°
24
67°
49°
25
63°
50°
26
64°
51°
27
66°
49°
28
65°
45°
29
70°
51°
30
69°
50°
1
68°
51°
2
70°
50°
3
68°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in McHenry
McHenry's September 2026 forecast shows daily high temperatures ranging from 63° to 82°, with overnight lows between 45° and 67°. The average high for September is 70° with an average low of 55°. 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 McHenry. See also: October | November | December.
