S
M
T
W
T
F
S
30
74°
60°
31
73°
60°
1
73°
61°
2
74°
64°
3
73°
62°
4
73°
64°
5
74°
65°
6
75°
66°
7
80°
66°
8
79°
65°
9
78°
65°
10
73°
64°
11
77°
65°
12
74°
65°
13
75°
64°
14
70°
63°
15
69°
63°
16
69°
62°
17
70°
63°
18
69°
62°
19
70°
61°
20
68°
61°
21
78°
61°
22
78°
56°
23
74°
51°
24
66°
52°
25
66°
59°
26
69°
58°
27
69°
59°
28
74°
58°
29
75°
56°
30
73°
56°
1
71°
58°
2
72°
56°
3
73°
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 66° to 80°, with overnight lows between 51° and 66°. The average high for September is 73° with an average low of 61°. 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.
