S
M
T
W
T
F
S
30
76°
55°
31
70°
55°
1
73°
51°
2
70°
49°
3
68°
57°
4
71°
60°
5
60°
54°
6
59°
51°
7
62°
51°
8
63°
47°
9
60°
44°
10
72°
55°
11
64°
48°
12
69°
47°
13
69°
49°
14
75°
52°
15
69°
49°
16
73°
48°
17
69°
52°
18
65°
48°
19
60°
46°
20
56°
40°
21
60°
45°
22
61°
41°
23
61°
39°
24
66°
42°
25
72°
41°
26
64°
51°
27
67°
51°
28
58°
47°
29
69°
57°
30
64°
57°
1
71°
56°
2
72°
53°
3
68°
44°
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 68° to 72°, with overnight lows between 44° and 56°. The average high for September is 70° with an average low of 51°. 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.
