Nantucket Beach Water Temperature
Sea-surface temperature at Nantucket Beach, Massachusetts · times in EDT
Updated 4:00 AM EDT
How it compares today
Water temperature through the year
Monthly normals computed from 2023–2025 daily sea-surface temperature history.
Nearby water right now
7-day outlook
| Day | Air high / low | Max UV | Rain |
|---|---|---|---|
| Tue, Oct 13 | 63° / 55° | 3 | 10% |
| Wed, Oct 14 | 68° / 63° | 5 | 17% |
| Thu, Oct 15 | 62° / 54° | 5 | 4% |
| Fri, Oct 16 | 65° / 54° | 2 | 75% |
| Sat, Oct 17 | 58° / 42° | 4 | 56% |
| Sun, Oct 18 | 57° / 41° | 4 | 2% |
| Mon, Oct 19 | 58° / 53° | 4 | 8% |
Sea-surface temperature and wave data from the Open-Meteo marine model; weather from Open-Meteo.
Is Nantucket Beach warm enough to swim?
At 62°F, the water at Nantucket Beach is chilly — wetsuit recommended. Most swimmers are comfortable without a wetsuit above 72°F; below 62°F, cold-water shock becomes a real risk for unprotected swimmers.
That is 1° above the October average of 61°F here.
The water here never averages above 70°F — even in August, the warmest month, it sits around 69°F. Most people wear a wetsuit.
Frequently asked questions
How warm is the water at Nantucket Beach right now?
The sea-surface temperature is about 62°F. That is 1° above the October average of 61°F here.
When is the water warm enough to swim at Nantucket Beach?
The water here never averages above 70°F — even in August, the warmest month, it sits around 69°F. Most people wear a wetsuit.
What is the warmest the water gets at Nantucket Beach?
Around 69°F in August, based on 2023–2025 records. The coolest month is February at roughly 39°F.