S
M
T
W
T
F
S
30
73°
51°
31
72°
50°
1
71°
51°
2
71°
51°
3
72°
52°
4
72°
53°
5
71°
52°
6
72°
51°
7
70°
50°
8
68°
49°
9
69°
48°
10
70°
53°
11
70°
51°
12
69°
49°
13
72°
48°
14
72°
52°
15
71°
51°
16
68°
47°
17
71°
46°
18
73°
49°
19
74°
53°
20
68°
53°
21
69°
52°
22
72°
52°
23
72°
48°
24
69°
45°
25
66°
50°
26
69°
43°
27
70°
42°
28
62°
43°
29
62°
43°
30
68°
49°
1
67°
43°
2
Hist. Avg.
63°
43°
3
Hist. Avg.
62°
43°
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 62° to 74°, with overnight lows between 42° and 53°. The average high for September is 70° 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 Bar Harbor. See also: October | November | December.
