S
M
T
W
T
F
S
30
84°
68°
31
86°
70°
1
95°
72°
2
90°
69°
3
81°
66°
4
80°
67°
5
79°
65°
6
79°
62°
7
75°
61°
8
70°
60°
9
74°
57°
10
73°
61°
11
72°
55°
12
70°
56°
13
72°
55°
14
74°
54°
15
76°
59°
16
77°
59°
17
75°
58°
18
74°
59°
19
76°
60°
20
77°
59°
21
77°
59°
22
76°
58°
23
76°
58°
24
75°
57°
25
76°
58°
26
76°
58°
27
75°
57°
28
75°
57°
29
74°
56°
30
73°
56°
1
73°
55°
2
72°
55°
3
73°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mequon
Mequon's September 2026 forecast shows daily high temperatures ranging from 70° to 95°, with overnight lows between 54° and 72°. The average high for September is 76° with an average low of 59°. 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 Mequon. See also: October | November | December.
