S
M
T
W
T
F
S
30
71°
48°
31
72°
56°
1
74°
47°
2
74°
50°
3
72°
47°
4
72°
46°
5
71°
50°
6
70°
51°
7
69°
49°
8
75°
51°
9
78°
46°
10
75°
50°
11
77°
50°
12
76°
51°
13
77°
52°
14
77°
52°
15
76°
53°
16
76°
51°
17
77°
44°
18
75°
41°
19
62°
38°
20
64°
40°
21
62°
40°
22
63°
48°
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 62° to 78°, with overnight lows between 38° and 56°. The average high for September is 72° with an average low of 48°. 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.
