Water temperature in Portsmouth (NH) in July
Is it warm enough to swim in Portsmouth in July? Average water temperature in Portsmouth in July is 64.4°F and therefore is not suitable for comfortable swimming. The warmest sea in Portsmouth in July is 71.8°F, and the coldest is 56.7°F. To find out the sea temperature today and in the coming days, go to Current sea temperature in Portsmouth
Changes water temperature in Portsmouth in July 2025, 2024
To get an accurate forecast for the water temperature in Portsmouth for any chosen month, compare two years within a 10 year range using the chart below. In addition to the sea water temperature in Portsmouth, the selected years in the table also show the values of the maximum and minimum temperatures on each of the days of July.
You can choose any other years:
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| July 1 | 63.7°F | 57.7°F | 57.4°F | 64.4°F |
| July 2 | 64.6°F | 57.7°F | 56.7°F | 64.8°F |
| July 3 | 64°F | 59.9°F | 57°F | 64.8°F |
| July 4 | 62.4°F | 59.2°F | 57.7°F | 66.6°F |
| July 5 | 62.6°F | 59.7°F | 58.8°F | 66.9°F |
| July 6 | 63.5°F | 60.4°F | 59.2°F | 67.8°F |
| July 7 | 63.7°F | 60.3°F | 59.7°F | 68.2°F |
| July 8 | 63.5°F | 61°F | 59.4°F | 68°F |
| July 9 | 63.5°F | 63.7°F | 59.4°F | 67.8°F |
| July 10 | 63.7°F | 63.3°F | 60.3°F | 67.5°F |
| July 11 | 64.8°F | 60.1°F | 60.1°F | 68.9°F |
| July 12 | 64°F | 61.7°F | 60.6°F | 69.8°F |
| July 13 | 64.2°F | 61.2°F | 61°F | 68.9°F |
| July 14 | 63.5°F | 62.2°F | 61.7°F | 68.5°F |
| July 15 | 64.6°F | 62.4°F | 61.5°F | 68.9°F |
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| July 16 | 65.1°F | 61.2°F | 60.8°F | 68.9°F |
| July 17 | 67.3°F | 61.3°F | 60.4°F | 69.3°F |
| July 18 | 65.5°F | 61°F | 60.4°F | 69.4°F |
| July 19 | 64.4°F | 60.6°F | 59.9°F | 70°F |
| July 20 | 64.4°F | 59.5°F | 59.2°F | 70°F |
| July 21 | 62.1°F | 61°F | 61°F | 70.3°F |
| July 22 | 61.5°F | 61.7°F | 61.3°F | 70.3°F |
| July 23 | 61.7°F | 62.4°F | 61.7°F | 70.2°F |
| July 24 | 62.8°F | 62.4°F | 61°F | 71.1°F |
| July 25 | 61.7°F | 61.3°F | 61.3°F | 70.5°F |
| July 26 | 61.2°F | 61.7°F | 61.2°F | 71.2°F |
| July 27 | 61.3°F | 63°F | 61.3°F | 70.7°F |
| July 28 | 61.9°F | 63.7°F | 61.9°F | 71.8°F |
| July 29 | 64.2°F | 62.6°F | 61.9°F | 71.4°F |
| July 30 | 65.3°F | 62.4°F | 62.4°F | 69.6°F |
| July 31 | 64.4°F | 63.9°F | 62.4°F | 70°F |
Average water temperature in Portsmouth in July over a decade
| 2016 | 2017 | 2018 | 2019 | 2020 |
| 65.3°F | 63°F | 65.5°F | 66°F | 67.6°F |
| 2021 | 2022 | 2023 | 2024 | 2025 |
| 63.9°F | 62.1°F | 67.5°F | 61.3°F | 63.5°F |
Portsmouth sea state in July
Chart comparing the height of waves in Portsmouth in July 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.
Portsmouth water temperature during other months:
You can also view information about water temperature for other months by clicking on the month button below
