S
M
T
W
T
F
S
30
73°
59°
31
71°
54°
1
67°
58°
2
70°
61°
3
75°
57°
4
74°
56°
5
73°
55°
6
72°
56°
7
75°
57°
8
74°
58°
9
73°
57°
10
77°
52°
11
69°
54°
12
70°
55°
13
72°
56°
14
75°
57°
15
75°
56°
16
73°
55°
17
74°
54°
18
71°
54°
19
72°
53°
20
66°
55°
21
73°
54°
22
72°
53°
23
70°
54°
24
73°
53°
25
65°
52°
26
66°
50°
27
67°
52°
28
70°
52°
29
70°
52°
30
71°
52°
1
71°
52°
2
69°
51°
3
69°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Bar Harbor
Bar Harbor's September 2026 forecast shows daily high temperatures ranging from 65° to 77°, with overnight lows between 50° and 61°. The average high for September is 71° with an average low of 54°. 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 Bar Harbor. See also: October | November | December.
