S
M
T
W
T
F
S
30
93°
72°
31
93°
71°
1
99°
73°
2
98°
77°
3
100°
75°
4
96°
72°
5
98°
71°
6
92°
70°
7
91°
68°
8
94°
69°
9
89°
62°
10
86°
59°
11
84°
56°
12
83°
58°
13
85°
60°
14
79°
55°
15
85°
61°
16
85°
60°
17
84°
62°
18
85°
62°
19
85°
60°
20
83°
61°
21
84°
62°
22
84°
61°
23
83°
60°
24
83°
60°
25
82°
59°
26
83°
57°
27
82°
58°
28
82°
58°
29
81°
57°
30
82°
58°
1
82°
58°
2
81°
57°
3
81°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Dorchester
Dorchester's September 2026 forecast shows daily high temperatures ranging from 79° to 100°, with overnight lows between 55° and 77°. The average high for September is 86° with an average low of 62°. 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 Dorchester. See also: October | November | December.
