S
M
T
W
T
F
S
30
70°
66°
31
76°
66°
1
83°
70°
2
80°
69°
3
80°
60°
4
78°
59°
5
75°
56°
6
71°
59°
7
75°
58°
8
69°
56°
9
70°
56°
10
72°
58°
11
70°
58°
12
70°
55°
13
69°
56°
14
68°
54°
15
71°
60°
16
74°
60°
17
73°
57°
18
66°
55°
19
69°
59°
20
74°
60°
21
74°
60°
22
73°
60°
23
74°
58°
24
72°
57°
25
72°
56°
26
71°
57°
27
72°
58°
28
72°
56°
29
71°
55°
30
66°
54°
1
66°
55°
2
69°
56°
3
70°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Dunnville
Dunnville's September 2026 forecast shows daily high temperatures ranging from 66° to 83°, with overnight lows between 54° and 70°. The average high for September is 72° with an average low of 58°. 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 Dunnville. See also: October | November | December.
