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
79°
63°
12
71°
56°
13
70°
63°
14
74°
58°
15
66°
53°
16
80°
56°
17
76°
64°
18
80°
62°
19
62°
54°
20
63°
55°
21
65°
55°
22
63°
53°
23
64°
51°
24
65°
51°
25
63°
58°
26
61°
55°
27
63°
56°
28
61°
58°
29
65°
58°
30
70°
59°
1
72°
60°
2
70°
59°
3
69°
56°
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 61° to 72°, with overnight lows between 51° and 60°. The average high for September is 66° 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.
