S
M
T
W
T
F
S
30
82°
61°
31
73°
63°
1
71°
60°
2
74°
58°
3
78°
64°
4
79°
62°
5
72°
59°
6
67°
53°
7
76°
56°
8
78°
58°
9
76°
58°
10
83°
69°
11
74°
55°
12
72°
49°
13
72°
58°
14
73°
55°
15
69°
56°
16
72°
62°
17
75°
66°
18
76°
60°
19
71°
57°
20
70°
58°
21
66°
56°
22
69°
57°
23
67°
56°
24
66°
55°
25
70°
56°
26
69°
55°
27
65°
55°
28
71°
56°
29
71°
55°
30
64°
55°
1
64°
54°
2
65°
55°
3
70°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Dennis
Dennis's September 2026 forecast shows daily high temperatures ranging from 64° to 76°, with overnight lows between 54° and 66°. The average high for September is 69° with an average low of 57°. 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 Dennis. See also: October | November | December.
