Water temperature in Nantucket (MA) in August
Is it warm enough to swim in Nantucket in August? Average water temperature in Nantucket in August is 68.5°F and therefore suitable for comfortable swimming. The warmest sea in Nantucket in August is 75°F, and the coldest is 63.1°F. Average high air temperature in Nantucket in August is 75°F, and average low temperature is 62°F. To find out the sea temperature today and in the coming days, go to Current sea temperature in Nantucket
Changes water temperature in Nantucket in August 2025, 2024
To get an accurate forecast for the water temperature in Nantucket for any chosen month, compare two years within a 10 year range using the chart below. In addition to the sea water temperature in Nantucket, the selected years in the table also show the values of the maximum and minimum temperatures on each of the days of August.
You can choose any other years:
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| August 1 | 68.4°F | 68.9°F | 64.9°F | 71.6°F |
| August 2 | 68.2°F | 70°F | 65.1°F | 71.8°F |
| August 3 | 67.5°F | 70.3°F | 65.3°F | 72.5°F |
| August 4 | 66.9°F | 69.4°F | 65.7°F | 72.3°F |
| August 5 | 66.6°F | 69.6°F | 66.2°F | 73.8°F |
| August 6 | 67.5°F | 70.2°F | 66°F | 73.6°F |
| August 7 | 66.7°F | 69.3°F | 65.8°F | 75°F |
| August 8 | 67.5°F | 69.4°F | 66.4°F | 73.9°F |
| August 9 | 67.6°F | 69.1°F | 65.8°F | 74.5°F |
| August 10 | 67.6°F | 69.1°F | 65.7°F | 73.6°F |
| August 11 | 68.5°F | 68.7°F | 65.8°F | 72.5°F |
| August 12 | 69.4°F | 68.2°F | 66.2°F | 72.1°F |
| August 13 | 69.1°F | 68.9°F | 66.6°F | 73.4°F |
| August 14 | 70.9°F | 70.2°F | 65.8°F | 73.4°F |
| August 15 | 70.5°F | 69.4°F | 66°F | 72.7°F |
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| August 16 | 69.4°F | 69.1°F | 66°F | 72.1°F |
| August 17 | 68.7°F | 66°F | 64.6°F | 72.1°F |
| August 18 | 68.4°F | 68.4°F | 63.5°F | 72°F |
| August 19 | 68.2°F | 67.8°F | 63.1°F | 72.5°F |
| August 20 | 66.7°F | 67.1°F | 64.2°F | 70.5°F |
| August 21 | 66.4°F | 69.3°F | 64.8°F | 71.8°F |
| August 22 | 65.5°F | 68°F | 64.8°F | 72°F |
| August 23 | 65.8°F | 68.5°F | 64.4°F | 72.1°F |
| August 24 | 66.6°F | 68.4°F | 64.6°F | 72.9°F |
| August 25 | 66.9°F | 68°F | 65.3°F | 72.3°F |
| August 26 | 67.5°F | 68.2°F | 64.8°F | 73°F |
| August 27 | 69.3°F | 68.7°F | 65.3°F | 73°F |
| August 28 | 67.5°F | 67.5°F | 65.7°F | 72.5°F |
| August 29 | 67.6°F | 68.2°F | 64.6°F | 71.4°F |
| August 30 | 67.6°F | 67.8°F | 64.9°F | 71.2°F |
| August 31 | 67.5°F | 67.6°F | 64.6°F | 71.1°F |
Average water temperature in Nantucket in August over a decade
| 2016 | 2017 | 2018 | 2019 | 2020 |
| 69.6°F | 66.2°F | 68.5°F | 70°F | 70.5°F |
| 2021 | 2022 | 2023 | 2024 | 2025 |
| 71.1°F | 71.1°F | 68.7°F | 68.7°F | 67.5°F |
Nantucket sea state in August
Chart comparing the height of waves in Nantucket in August over the past years. The red line indicates the height of the waves when swimming in the sea is prohibited. To view the current sea conditions, click on the graph.
Weather and climate in Nantucket in August
This data display average monthly climate indicators in Nantucket in August based on our historical weather readings over a period of ten years. In addition to temperature, we include data on the number of rainy and sunny days so you can have all the information about your destination before your trip
- Average HIGH temperature75°F
- Average LOW temperature62°F
- Average rainfall days9 days
- Average rainfall99mm/3.9''
- Average daylight14h
- Average sunshine8h
- Average UV index8
Nantucket water temperature during other months:
You can also view information about water temperature for other months by clicking on the month button below
