S
M
T
W
T
F
S
30
73°
59°
31
72°
57°
1
73°
61°
2
74°
64°
3
73°
67°
4
82°
67°
5
82°
66°
6
81°
58°
7
80°
57°
8
73°
59°
9
73°
57°
10
71°
59°
11
71°
61°
12
70°
59°
13
74°
58°
14
74°
62°
15
73°
62°
16
70°
60°
17
72°
61°
18
74°
60°
19
75°
54°
20
72°
57°
21
71°
54°
22
74°
52°
23
67°
52°
24
67°
53°
25
66°
54°
26
66°
51°
27
67°
51°
28
65°
54°
29
64°
49°
30
65°
49°
1
64°
54°
2
70°
51°
3
69°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Boston
Boston's September 2026 forecast shows daily high temperatures ranging from 64° to 82°, with overnight lows between 49° and 67°. The average high for September is 72° with an average low of 57°. 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 Boston. See also: October | November | December.
