Measurements:
°C
°F
Nantucket
62°F
SE 28 mph
Feels like: 62°F
Precip: 3%
World Resorts USA Nantucket Weather

Nantucket Sea Water Temperature

Current Sea Water Temperature:
+63.2°F
Maximum Sea Water Temperature in October: 70.6°F
Minimum Sea Water Temperature in October: 56.6°F
Average water temperature in October: 63.0°F

Sea Water Temperature for the Last 10 Days:

October 05 63.2°F September 30 60.0°F
October 04 63.4°F September 29 63.6°F
October 03 59.8°F September 28 64.6°F
October 02 56.6°F September 27 64.0°F
October 01 56.8°F September 26 64.6°F

When is the Warmest Sea for Nantucket?

According to our data for the last three years for Nantucket 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 Nantucket was 73.9°F. The maximum and minimum values were 69.6°F and 76.4°F respectively.

Sea Water Temperature in July

Select Year: 2026 2025 2024

The average sea surface temperature in July 2026 for Nantucket was 71.7°F. The maximum and minimum values were 68.6°F and 74.2°F respectively.

Sea Water Temperature in September

Select Year: 2026 2025 2024

The average sea surface temperature in September 2026 for Nantucket was 69.7°F. The maximum and minimum values were 60.0°F and 74.8°F respectively.

Best Time to Visit Nantucket
The most sunny months:
June 14 days
October 13 days
July 12 days
The most warm months:
August 74.1 °F
July 73.9 °F
September 69.0 °F
Warmest sea temperature:
August 74.3 °F
July 72.3 °F
September 70.5 °F
The most cold months:
February 34.6 °F
January 34.9 °F
March 39.7 °F
The most rainy months:
October 4 days
January 3 days
December 3 days
The most windy months:
January 19 mph
March 19 mph
December 19 mph

Nantucket 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
Nantucket
Local time: 20:26
05 oct, monday
2100 62°F
SE
28 mph
06 oct, tuesday
0000 60°F
SE
26 mph
0300 56°F
SE
24 mph
0600 54°F
SE
27 mph
0900 50°F
SE
22 mph
1200 52°F
SE
16 mph
1500 58°F
E
16 mph
1800 60°F
SE
17 mph