S
M
T
W
T
F
S
30
70°
49°
31
71°
51°
1
72°
48°
2
72°
49°
3
77°
55°
4
75°
54°
5
77°
54°
6
78°
53°
7
79°
54°
8
77°
56°
9
79°
48°
10
78°
44°
11
73°
43°
12
66°
42°
13
66°
43°
14
67°
42°
15
65°
42°
16
66°
43°
17
67°
46°
18
72°
42°
19
76°
41°
20
65°
39°
21
64°
40°
22
61°
42°
23
Hist. Avg.
65°
41°
24
Hist. Avg.
64°
41°
25
Hist. Avg.
64°
40°
26
Hist. Avg.
64°
40°
27
Hist. Avg.
63°
39°
28
Hist. Avg.
62°
39°
29
Hist. Avg.
62°
38°
30
Hist. Avg.
62°
38°
1
Hist. Avg.
61°
38°
2
Hist. Avg.
61°
37°
3
Hist. Avg.
60°
37°
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 61° to 79°, with overnight lows between 39° and 56°. The average high for September is 71° with an average low of 47°. 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.
