S
M
T
W
T
F
S
30
69°
53°
31
70°
51°
1
68°
51°
2
67°
49°
3
68°
50°
4
69°
52°
5
68°
56°
6
69°
51°
7
68°
50°
8
67°
51°
9
67°
49°
10
66°
54°
11
68°
51°
12
67°
49°
13
68°
49°
14
68°
48°
15
65°
47°
16
65°
47°
17
66°
48°
18
65°
52°
19
68°
54°
20
69°
52°
21
70°
52°
22
70°
51°
23
65°
50°
24
68°
47°
25
62°
44°
26
63°
46°
27
66°
45°
28
65°
44°
29
59°
44°
30
59°
43°
1
Hist. Avg.
61°
46°
2
Hist. Avg.
60°
45°
3
Hist. Avg.
60°
45°
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 59° to 70°, with overnight lows between 43° and 56°. The average high for September is 67° with an average low of 49°. 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.
