S
M
T
W
T
F
S
30
94°
71°
31
94°
71°
1
93°
70°
2
93°
71°
3
92°
71°
4
93°
70°
5
92°
70°
6
92°
69°
7
91°
69°
8
91°
68°
9
90°
69°
10
91°
69°
11
91°
68°
12
90°
70°
13
91°
67°
14
81°
63°
15
78°
66°
16
89°
65°
17
90°
60°
18
87°
53°
19
76°
52°
20
78°
55°
21
81°
60°
22
84°
61°
23
85°
61°
24
86°
60°
25
83°
60°
26
84°
59°
27
84°
50°
28
76°
48°
29
74°
52°
30
77°
58°
1
82°
58°
2
83°
57°
3
84°
58°
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 74° to 94°, with overnight lows between 48° and 71°. The average high for September is 86° with an average low of 63°. 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.
