S
M
T
W
T
F
S
30
81°
64°
31
84°
66°
1
86°
62°
2
80°
60°
3
79°
59°
4
79°
58°
5
80°
58°
6
80°
62°
7
83°
59°
8
83°
63°
9
84°
63°
10
84°
62°
11
83°
61°
12
83°
63°
13
82°
63°
14
83°
62°
15
83°
63°
16
82°
62°
17
81°
61°
18
81°
61°
19
80°
60°
20
81°
60°
21
79°
59°
22
80°
52°
23
74°
52°
24
Hist. Avg.
77°
53°
25
Hist. Avg.
77°
53°
26
Hist. Avg.
77°
52°
27
Hist. Avg.
76°
52°
28
Hist. Avg.
76°
51°
29
Hist. Avg.
76°
51°
30
Hist. Avg.
75°
50°
1
Hist. Avg.
75°
50°
2
Hist. Avg.
75°
50°
3
Hist. Avg.
74°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in McHenry
McHenry's September 2026 forecast shows daily high temperatures ranging from 74° to 86°, with overnight lows between 52° and 66°. The average high for September is 81° with an average low of 61°. 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.
