S
M
T
W
T
F
S
30
79°
64°
31
72°
65°
1
70°
61°
2
70°
63°
3
78°
68°
4
82°
67°
5
74°
63°
6
71°
60°
7
77°
59°
8
78°
62°
9
75°
62°
10
79°
69°
11
75°
62°
12
71°
57°
13
72°
66°
14
73°
60°
15
67°
58°
16
71°
64°
17
75°
66°
18
77°
57°
19
66°
60°
20
67°
60°
21
68°
60°
22
64°
55°
23
65°
57°
24
67°
59°
25
69°
58°
26
68°
59°
27
66°
57°
28
67°
47°
29
72°
55°
30
65°
53°
1
64°
54°
2
66°
55°
3
71°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Block Island
Block Island's September 2026 forecast shows daily high temperatures ranging from 64° to 77°, with overnight lows between 47° and 66°. The average high for September is 68° 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 Block Island. See also: October | November | December.
