Measurements:
°C
°F
CURRENT WEATHER
11:12
Block Island
64°F
W 9 mph
Feels like: 64°F
Precip: 4%
World Resorts USA Block Island Weather

7 Day Weather Forecast

09.15
tue
DAY
64°F
W 9 mph
precip
4%
NIGHT
66°F
NW 8 mph
precip
5%
09.16
wed
DAY
68°F
NE 12 mph
precip
11%
NIGHT
70°F
E 11 mph
precip
11%
09.17
thu
DAY
72°F
NE 11 mph
precip
13%
NIGHT
72°F
NE 14 mph
precip
25%
09.18
fri
DAY
72°F
SE 11 mph
precip
22%
NIGHT
64°F
SW 19 mph
precip
13%
09.19
sat
DAY
62°F
W 12 mph
precip
11%
NIGHT
64°F
NW 15 mph
precip
16%
09.20
sun
DAY
68°F
N 26 mph
precip
86%
NIGHT
62°F
S 21 mph
precip
28%
09.21
mon
DAY
64°F
SW 15 mph
precip
15%
NIGHT
64°F
W 14 mph
precip
17%

Block Island Sea Water Temperature in September, °F

Select Year: 2026 2025 2024

The average sea surface temperature in September 2026 for Block Island was 20.6°F. The maximum and minimum values were 20.1°F and 21.3°F respectively.

Block Island on the Weather Map

Best Time to Visit Block Island
The most sunny months:
November 16 days
December 14 days
June 14 days
The most warm months:
July 77.6 °F
August 76.8 °F
September 70.9 °F
Warmest sea temperature:
August 72.3 °F
July 70.5 °F
September 70.3 °F
The most cold months:
January 35.4 °F
February 35.4 °F
December 41.7 °F
The most rainy months:
October 4 days
January 3 days
March 3 days
The most windy months:
December 16 mph
January 16 mph
November 16 mph
more details