Water temperature in Key West (FL) in March
Is it warm enough to swim in Key West in March? Average water temperature in Key West in March is 75.9°F and therefore suitable for comfortable swimming. The warmest sea in Key West in March is 79.9°F, and the coldest is 70.3°F. Average high air temperature in Key West in March is 78°F, and average low temperature is 68°F. To find out the sea temperature today and in the coming days, go to Current sea temperature in Key West
Changes water temperature in Key West in March 2026, 2025
To get an accurate forecast for the water temperature in Key West for any chosen month, compare two years within a 10 year range using the chart below. In addition to the sea water temperature in Key West, the selected years in the table also show the values of the maximum and minimum temperatures on each of the days of March.
You can choose any other years:
| Day | 2026 | 2025 | Min | Max |
|---|---|---|---|---|
| March 1 | 76.3°F | 74.3°F | 71.4°F | 79°F |
| March 2 | 76.3°F | 75°F | 71.2°F | 79°F |
| March 3 | 77°F | 75.2°F | 71.4°F | 79.3°F |
| March 4 | 76.8°F | 74.8°F | 71.4°F | 79.2°F |
| March 5 | 77°F | 75.6°F | 70.7°F | 78.6°F |
| March 6 | 77.2°F | 75.4°F | 71.2°F | 78.3°F |
| March 7 | 75°F | 70.5°F | 78.4°F | |
| March 8 | 75.2°F | 70.3°F | 78.6°F | |
| March 9 | 75.4°F | 70.9°F | 78.4°F | |
| March 10 | 75.6°F | 70.9°F | 79.2°F | |
| March 11 | 74.7°F | 71.2°F | 79.3°F | |
| March 12 | 74.7°F | 72°F | 79.5°F | |
| March 13 | 75.6°F | 72.3°F | 78.8°F | |
| March 14 | 76.5°F | 71.8°F | 78.4°F | |
| March 15 | 76.5°F | 72°F | 78.3°F |
| Day | 2026 | 2025 | Min | Max |
|---|---|---|---|---|
| March 16 | 76.3°F | 71.8°F | 78.6°F | |
| March 17 | 75.6°F | 72.1°F | 78.4°F | |
| March 18 | 75.2°F | 72.3°F | 78.4°F | |
| March 19 | 75.4°F | 72.9°F | 78.8°F | |
| March 20 | 75.4°F | 72.3°F | 79°F | |
| March 21 | 74.5°F | 72.7°F | 78.6°F | |
| March 22 | 75°F | 72.5°F | 78.6°F | |
| March 23 | 75.4°F | 72.7°F | 78.8°F | |
| March 24 | 75.6°F | 73.4°F | 79°F | |
| March 25 | 75.4°F | 73.2°F | 78.6°F | |
| March 26 | 75.7°F | 73.6°F | 79.2°F | |
| March 27 | 76.1°F | 72.5°F | 79.5°F | |
| March 28 | 76.3°F | 72°F | 78.8°F | |
| March 29 | 76.6°F | 71.6°F | 79.3°F | |
| March 30 | 77.7°F | 72°F | 79.3°F | |
| March 31 | 78.8°F | 72.7°F | 79.9°F |
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Average water temperature in Key West in March over a decade
| 2016 | 2017 | 2018 | 2019 | 2020 |
| 76.1°F | 75.9°F | 76.3°F | 77.5°F | 77.2°F |
| 2021 | 2022 | 2023 | 2024 | 2025 |
| 76.5°F | 77.9°F | 78.1°F | 76.8°F | 75.6°F |
Key West sea state in March
Chart comparing the height of waves in Key West in March 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 Key West in March
This data display average monthly climate indicators in Key West in March 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 temperature78°F
- Average LOW temperature68°F
- Average humidity
73 - Average rainfall days6 days
- Average rainfall41mm/1.6''
- Average daylight12h
- Average sunshine10h
- Average UV index10
Key West water temperature during other months:
You can also view information about water temperature for other months by clicking on the month button below
