S
M
T
W
T
F
S
30
77°
55°
31
77°
55°
1
78°
59°
2
78°
58°
3
79°
58°
4
78°
61°
5
79°
61°
6
83°
62°
7
83°
62°
8
82°
61°
9
80°
60°
10
79°
60°
11
80°
61°
12
78°
60°
13
77°
59°
14
73°
59°
15
72°
58°
16
72°
57°
17
72°
55°
18
75°
57°
19
75°
57°
20
76°
55°
21
81°
57°
22
81°
50°
23
78°
47°
24
72°
49°
25
70°
51°
26
69°
55°
27
76°
54°
28
76°
53°
29
77°
52°
30
77°
51°
1
76°
52°
2
75°
52°
3
76°
53°
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 69° to 83°, with overnight lows between 47° and 62°. The average high for September is 77° 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 Hamilton. See also: October | November | December.