S
M
T
W
T
F
S
30
79°
67°
31
79°
67°
1
82°
62°
2
78°
61°
3
77°
63°
4
80°
62°
5
76°
62°
6
76°
60°
7
74°
58°
8
74°
60°
9
72°
52°
10
70°
56°
11
72°
56°
12
73°
56°
13
74°
57°
14
74°
57°
15
73°
56°
16
74°
55°
17
69°
55°
18
74°
56°
19
70°
56°
20
72°
55°
21
72°
56°
22
73°
56°
23
73°
53°
24
68°
52°
25
61°
50°
26
64°
52°
27
68°
52°
28
69°
51°
29
70°
52°
30
70°
52°
1
69°
51°
2
69°
52°
3
67°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Waterdown
Waterdown's September 2026 forecast shows daily high temperatures ranging from 61° to 82°, with overnight lows between 50° and 67°. The average high for September is 72° with an average low of 56°. 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 Waterdown. See also: October | November | December.