S
M
T
W
T
F
S
30
78°
57°
31
73°
53°
1
71°
55°
2
71°
53°
3
72°
52°
4
71°
54°
5
72°
59°
6
73°
59°
7
76°
57°
8
78°
55°
9
77°
56°
10
72°
58°
11
78°
57°
12
77°
56°
13
76°
58°
14
76°
55°
15
78°
47°
16
74°
46°
17
67°
45°
18
67°
52°
19
70°
52°
20
70°
54°
21
72°
54°
22
69°
53°
23
73°
54°
24
74°
52°
25
70°
53°
26
74°
54°
27
73°
45°
28
73°
42°
29
71°
42°
30
61°
46°
1
60°
41°
2
63°
47°
3
62°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Hamilton
Hamilton's September 2026 forecast shows daily high temperatures ranging from 60° to 78°, with overnight lows between 41° and 59°. The average high for September is 72° 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 Hamilton. See also: October | November | December.