S
M
T
W
T
F
S
30
86°
65°
31
73°
63°
1
69°
63°
2
72°
64°
3
73°
63°
4
85°
66°
5
73°
64°
6
68°
59°
7
82°
59°
8
81°
64°
9
76°
61°
10
87°
71°
11
77°
54°
12
73°
64°
13
73°
63°
14
74°
52°
15
69°
58°
16
78°
66°
17
78°
63°
18
74°
58°
19
68°
57°
20
68°
54°
21
67°
54°
22
69°
55°
23
68°
56°
24
72°
55°
25
64°
51°
26
64°
54°
27
65°
57°
28
68°
56°
29
64°
55°
30
64°
55°
1
65°
58°
2
68°
57°
3
68°
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 64° to 78°, with overnight lows between 51° and 66°. The average high for September is 69° 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.
