S
M
T
W
T
F
S
30
83°
54°
31
77°
62°
1
69°
62°
2
73°
65°
3
75°
62°
4
82°
60°
5
76°
62°
6
73°
60°
7
77°
64°
8
78°
62°
9
78°
67°
10
79°
65°
11
77°
64°
12
76°
64°
13
78°
62°
14
76°
59°
15
72°
61°
16
74°
63°
17
77°
62°
18
71°
58°
19
71°
60°
20
73°
61°
21
76°
62°
22
78°
63°
23
78°
62°
24
77°
61°
25
76°
60°
26
77°
60°
27
76°
61°
28
76°
60°
29
75°
59°
30
68°
54°
1
66°
55°
2
66°
58°
3
73°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Dartmouth
Dartmouth's September 2026 forecast shows daily high temperatures ranging from 66° to 82°, with overnight lows between 54° and 67°. The average high for September is 75° with an average low of 61°. 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 Dartmouth. See also: October | November | December.
