Measurements:
°C
°F
Block Island
60°F
SE 21 mph
Feels like: 56°F
Precip: 2%
World Resorts USA Block Island Weather

Block Island Sea Water Temperature

Current Sea Water Temperature:
+66.0°F
Maximum Sea Water Temperature in October: 70.4°F
Minimum Sea Water Temperature in October: 61.0°F
Average water temperature in October: 65.1°F

Sea Water Temperature for the Last 10 Days:

October 05 66.0°F September 30 64.0°F
October 04 66.6°F September 29 66.2°F
October 03 66.2°F September 28 65.6°F
October 02 66.8°F September 27 66.8°F
October 01 66.6°F September 26 66.8°F

When is the Warmest Sea for Block Island?

According to our data for the last three years for Block Island the highest average sea water temperature was in August, July and September.

Average Water Temperature by Month, °F

Sea Water Temperature in August

Select Year: 2026 2025 2024

The average sea surface temperature in August 2026 for Block Island was 72.5°F. The maximum and minimum values were 70.6°F and 74.8°F respectively.

Sea Water Temperature in July

Select Year: 2026 2025 2024

The average sea surface temperature in July 2026 for Block Island was 69.2°F. The maximum and minimum values were 67.2°F and 71.4°F respectively.

Sea Water Temperature in September

Select Year: 2026 2025 2024

The average sea surface temperature in September 2026 for Block Island was 69.9°F. The maximum and minimum values were 64.0°F and 72.6°F respectively.

Best Time to Visit Block Island
The most sunny months:
November 16 days
June 14 days
October 14 days
The most warm months:
July 77.6 °F
August 76.8 °F
September 71.0 °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

Block Island on the Weather Map

USA Resorts:
NAME
F°
Boston +58
Chicago +62
Hawaii +82
Houston +86
Las Vegas +92
Los Angeles +100
Maui +74
Miami +88
Myrtle Beach +70
New York +62
San Diego +84
San Francisco +66
Santa Monica +94
Sarasota +84
Washington +64
24 Hours Weather Forecast
Block Island
Local time: 19:52
05 oct, monday
2100 60°F
SE
21 mph
06 oct, tuesday
0000 56°F
SE
21 mph
0300 54°F
SE
19 mph
0600 50°F
SE
22 mph
0900 48°F
SE
19 mph
1200 54°F
SE
17 mph
1500 60°F
SE
18 mph
1800 60°F
SE
16 mph