S
M
T
W
T
F
S
30
86°
65°
31
73°
63°
1
69°
62°
2
72°
63°
3
74°
64°
4
81°
61°
5
74°
59°
6
69°
57°
7
75°
62°
8
74°
62°
9
72°
64°
10
78°
63°
11
74°
61°
12
75°
60°
13
74°
58°
14
72°
59°
15
70°
61°
16
72°
62°
17
76°
61°
18
69°
58°
19
69°
59°
20
70°
61°
21
74°
62°
22
76°
62°
23
76°
61°
24
75°
60°
25
74°
60°
26
75°
59°
27
74°
60°
28
74°
59°
29
73°
58°
30
66°
53°
1
63°
54°
2
63°
57°
3
71°
57°
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 63° to 81°, with overnight lows between 53° and 64°. The average high for September is 73° with an average low of 60°. 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.
