S
M
T
W
T
F
S
30
79°
65°
31
77°
62°
1
74°
63°
2
73°
63°
3
71°
61°
4
72°
62°
5
75°
63°
6
72°
61°
7
75°
65°
8
75°
64°
9
74°
64°
10
75°
63°
11
73°
64°
12
74°
64°
13
77°
62°
14
73°
60°
15
72°
61°
16
74°
62°
17
73°
62°
18
75°
57°
19
76°
55°
20
67°
54°
21
69°
61°
22
74°
60°
23
74°
60°
24
73°
57°
25
66°
56°
26
65°
54°
27
64°
51°
28
64°
54°
29
65°
54°
30
64°
52°
1
65°
58°
2
67°
54°
3
62°
54°
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 62° to 79°, with overnight lows between 51° and 65°. The average high for September is 71° with an average low of 59°. 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.
