S
M
T
W
T
F
S
30
83°
59°
31
78°
59°
1
75°
60°
2
76°
65°
3
76°
59°
4
79°
66°
5
76°
66°
6
81°
60°
7
79°
59°
8
72°
58°
9
74°
57°
10
72°
63°
11
74°
57°
12
77°
57°
13
71°
56°
14
70°
62°
15
74°
63°
16
76°
54°
17
78°
53°
18
68°
53°
19
67°
54°
20
68°
54°
21
68°
55°
22
66°
55°
23
66°
56°
24
67°
57°
25
69°
56°
26
72°
59°
27
72°
56°
28
73°
50°
29
65°
50°
30
63°
56°
1
64°
57°
2
69°
58°
3
70°
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 63° to 83°, with overnight lows between 50° and 66°. The average high for September is 72° with an average low of 58°. 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.
