S
M
T
W
T
F
S
30
75°
62°
31
78°
63°
1
80°
63°
2
80°
62°
3
79°
56°
4
79°
55°
5
72°
56°
6
73°
61°
7
74°
61°
8
77°
60°
9
78°
61°
10
77°
60°
11
76°
59°
12
77°
58°
13
77°
60°
14
76°
61°
15
78°
61°
16
78°
56°
17
76°
60°
18
74°
57°
19
76°
55°
20
71°
51°
21
68°
50°
22
68°
56°
23
69°
54°
24
73°
50°
25
67°
49°
26
66°
49°
27
67°
54°
28
72°
56°
29
71°
52°
30
71°
51°
1
64°
54°
2
65°
47°
3
64°
52°
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 80°, with overnight lows between 47° and 63°. The average high for September is 73° with an average low of 56°. 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.
