Water temperature in Foster City (CA) in April
Is it warm enough to swim in Foster City in April? Average water temperature in Foster City in April is 56.5°F and therefore is not suitable for comfortable swimming. The warmest sea in Foster City in April is 65.5°F, and the coldest is 50.7°F. To find out the sea temperature today and in the coming days, go to Current sea temperature in Foster City
Changes water temperature in Foster City in April 2025, 2024
To get an accurate forecast for the water temperature in Foster City for any chosen month, compare two years within a 10 year range using the chart below. In addition to the sea water temperature in Foster City, the selected years in the table also show the values of the maximum and minimum temperatures on each of the days of April.
You can choose any other years:
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| April 1 | 57.4°F | 58.3°F | 51.4°F | 61.2°F |
| April 2 | 57.9°F | 60.4°F | 51.4°F | 61.5°F |
| April 3 | 57.6°F | 60.6°F | 51.4°F | 60.6°F |
| April 4 | 57.4°F | 59.7°F | 51.3°F | 59.9°F |
| April 5 | 57.9°F | 59.2°F | 51.3°F | 60.3°F |
| April 6 | 59.5°F | 57.7°F | 51.3°F | 60.3°F |
| April 7 | 58.5°F | 57.6°F | 51.3°F | 62.1°F |
| April 8 | 58.6°F | 58.5°F | 51.3°F | 62.4°F |
| April 9 | 60.6°F | 59.7°F | 51.6°F | 63°F |
| April 10 | 62.1°F | 59.5°F | 51.4°F | 62.1°F |
| April 11 | 61.5°F | 61.3°F | 51.8°F | 61.5°F |
| April 12 | 61.5°F | 61°F | 52.2°F | 61.5°F |
| April 13 | 62.1°F | 59.9°F | 52°F | 62.1°F |
| April 14 | 62.6°F | 59.4°F | 51.3°F | 62.6°F |
| April 15 | 62.2°F | 59°F | 51.3°F | 62.2°F |
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| April 16 | 61.9°F | 59.9°F | 50.7°F | 62.2°F |
| April 17 | 62.4°F | 60.3°F | 50.7°F | 62.4°F |
| April 18 | 61.7°F | 62.2°F | 51.1°F | 62.2°F |
| April 19 | 61.7°F | 62.4°F | 51.3°F | 63°F |
| April 20 | 63.7°F | 61.9°F | 50.9°F | 63.7°F |
| April 21 | 63.5°F | 63.9°F | 50.7°F | 63.9°F |
| April 22 | 63.9°F | 65.3°F | 51.1°F | 65.3°F |
| April 23 | 63.7°F | 65.1°F | 51.3°F | 65.1°F |
| April 24 | 62.6°F | 64°F | 51.6°F | 64°F |
| April 25 | 61.9°F | 61.5°F | 51.4°F | 63.1°F |
| April 26 | 61.3°F | 62.8°F | 51.3°F | 63.9°F |
| April 27 | 60.4°F | 61.9°F | 51.3°F | 65.5°F |
| April 28 | 60.3°F | 61.7°F | 51.4°F | 64.2°F |
| April 29 | 61°F | 61.9°F | 51.1°F | 64.8°F |
| April 30 | 61.7°F | 61.7°F | 50.7°F | 64.8°F |
Average water temperature in Foster City in April over a decade
| 2016 | 2017 | 2018 | 2019 | 2020 |
| 57.7°F | 56.5°F | 60.6°F | 61.3°F | 60.3°F |
| 2021 | 2022 | 2023 | 2024 | 2025 |
| 60.1°F | 59.5°F | 57.4°F | 61°F | 61°F |
Foster City sea state in April
Chart comparing the height of waves in Foster City in April 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.
Foster City water temperature during other months:
You can also view information about water temperature for other months by clicking on the month button below
