S
M
T
W
T
F
S
30
79°
52°
31
76°
52°
1
73°
54°
2
74°
59°
3
73°
53°
4
74°
58°
5
71°
58°
6
78°
53°
7
75°
52°
8
71°
51°
9
72°
50°
10
70°
55°
11
71°
48°
12
72°
48°
13
69°
47°
14
68°
55°
15
72°
54°
16
72°
45°
17
73°
45°
18
65°
44°
19
64°
45°
20
65°
47°
21
65°
48°
22
63°
47°
23
63°
48°
24
66°
49°
25
67°
48°
26
70°
52°
27
70°
45°
28
71°
41°
29
61°
41°
30
60°
48°
1
61°
49°
2
66°
49°
3
65°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Harpswell
Harpswell's September 2026 forecast shows daily high temperatures ranging from 60° to 79°, with overnight lows between 41° and 59°. The average high for September is 69° with an average low of 50°. 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 Harpswell. See also: October | November | December.
