S
M
T
W
T
F
S
30
75°
65°
31
85°
65°
1
85°
57°
2
83°
57°
3
81°
59°
4
82°
58°
5
78°
57°
6
78°
58°
7
76°
58°
8
73°
53°
9
76°
52°
10
62°
36°
11
75°
54°
12
75°
54°
13
74°
53°
14
74°
52°
15
75°
51°
16
65°
50°
17
69°
51°
18
68°
51°
19
74°
52°
20
73°
52°
21
74°
51°
22
74°
50°
23
72°
47°
24
61°
48°
25
64°
48°
26
69°
49°
27
70°
49°
28
71°
50°
29
71°
49°
30
69°
49°
1
69°
47°
2
65°
47°
3
65°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Niagara
Niagara's September 2026 forecast shows daily high temperatures ranging from 61° to 85°, with overnight lows between 36° and 65°. The average high for September is 73° with an average low of 52°. 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. See also: October | November | December.
