S
M
T
W
T
F
S
30
71°
67°
31
74°
67°
1
79°
67°
2
82°
69°
3
79°
62°
4
78°
62°
5
74°
59°
6
75°
61°
7
76°
59°
8
72°
58°
9
73°
59°
10
75°
60°
11
73°
60°
12
74°
56°
13
71°
56°
14
74°
54°
15
73°
60°
16
76°
59°
17
76°
57°
18
69°
55°
19
73°
58°
20
77°
60°
21
78°
60°
22
78°
59°
23
77°
58°
24
76°
57°
25
76°
58°
26
75°
57°
27
76°
58°
28
76°
57°
29
74°
55°
30
68°
55°
1
68°
54°
2
73°
56°
3
73°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Niagara-on-the-Lake
Niagara-on-the-Lake's September 2026 forecast shows daily high temperatures ranging from 68° to 82°, with overnight lows between 54° and 69°. The average high for September is 75° 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 Niagara-on-the-Lake. See also: October | November | December.
