S
M
T
W
T
F
S
30
77°
61°
31
76°
62°
1
81°
58°
2
76°
58°
3
77°
56°
4
75°
55°
5
74°
55°
6
78°
59°
7
78°
58°
8
77°
60°
9
80°
60°
10
74°
59°
11
76°
59°
12
79°
58°
13
78°
59°
14
79°
59°
15
78°
58°
16
78°
52°
17
76°
55°
18
69°
58°
19
75°
57°
20
77°
57°
21
76°
56°
22
75°
48°
23
72°
54°
24
71°
54°
25
Hist. Avg.
71°
51°
26
Hist. Avg.
71°
51°
27
Hist. Avg.
70°
50°
28
Hist. Avg.
70°
50°
29
Hist. Avg.
70°
49°
30
Hist. Avg.
69°
49°
1
Hist. Avg.
69°
49°
2
Hist. Avg.
68°
48°
3
Hist. Avg.
68°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Boston
Boston's September 2026 forecast shows daily high temperatures ranging from 69° to 81°, with overnight lows between 48° and 62°. The average high for September is 76° 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.
