Water temperature in Marathon Key (FL) in June
Is it warm enough to swim in Marathon Key in June? Average water temperature in Marathon Key in June is 84.6°F and therefore suitable for comfortable swimming. The warmest sea in Marathon Key in June is 87.8°F, and the coldest is 79.3°F. To find out the sea temperature today and in the coming days, go to Current sea temperature in Marathon Key
Changes water temperature in Marathon Key in June 2025, 2024
To get an accurate forecast for the water temperature in Marathon Key for any chosen month, compare two years within a 10 year range using the chart below. In addition to the sea water temperature in Marathon Key, the selected years in the table also show the values of the maximum and minimum temperatures on each of the days of June.
You can choose any other years:
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| June 1 | 85.3°F | 85.8°F | 79.5°F | 85.8°F |
| June 2 | 85.3°F | 85.5°F | 79.7°F | 85.6°F |
| June 3 | 85.1°F | 85.5°F | 79.3°F | 85.5°F |
| June 4 | 85.1°F | 85.1°F | 80.1°F | 85.1°F |
| June 5 | 84.7°F | 85.6°F | 81.1°F | 85.6°F |
| June 6 | 84.2°F | 85.5°F | 82.2°F | 85.8°F |
| June 7 | 84.6°F | 86.4°F | 82°F | 86.4°F |
| June 8 | 84.6°F | 86.5°F | 81.9°F | 86.5°F |
| June 9 | 84.7°F | 87.1°F | 81.9°F | 87.3°F |
| June 10 | 84.9°F | 86.7°F | 82°F | 86.7°F |
| June 11 | 84.2°F | 86.5°F | 82.2°F | 86.5°F |
| June 12 | 85.6°F | 85.8°F | 82°F | 86.7°F |
| June 13 | 84.9°F | 85.3°F | 82.6°F | 87.1°F |
| June 14 | 85.5°F | 85.1°F | 82.6°F | 86.9°F |
| June 15 | 85.5°F | 85.1°F | 82.9°F | 86.7°F |
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| June 16 | 85.3°F | 84.4°F | 83.5°F | 86.7°F |
| June 17 | 85.1°F | 84.6°F | 83.5°F | 86.9°F |
| June 18 | 85.1°F | 84.9°F | 83.5°F | 87.4°F |
| June 19 | 85.3°F | 84.6°F | 83.1°F | 87.1°F |
| June 20 | 85.8°F | 84.2°F | 83.3°F | 87.6°F |
| June 21 | 85.5°F | 84.4°F | 83.5°F | 87.3°F |
| June 22 | 84.4°F | 83.5°F | 87.3°F | |
| June 23 | 84.9°F | 84.4°F | 83.5°F | 87.1°F |
| June 24 | 85.1°F | 84.9°F | 83.3°F | 87.3°F |
| June 25 | 85.3°F | 84.9°F | 83.7°F | 87.1°F |
| June 26 | 84.7°F | 86.2°F | 83.3°F | 87.1°F |
| June 27 | 84.6°F | 85.8°F | 83.5°F | 87.3°F |
| June 28 | 84.2°F | 85.8°F | 83.7°F | 86.9°F |
| June 29 | 84.4°F | 85.5°F | 83.7°F | 87.3°F |
| June 30 | 84.9°F | 85.5°F | 83.8°F | 87.8°F |
Average water temperature in Marathon Key in June over a decade
| 2016 | 2017 | 2018 | 2019 | 2020 |
| 84.9°F | 83.8°F | 84.6°F | 85.8°F | 84.9°F |
| 2021 | 2022 | 2023 | 2024 | 2025 |
| 83.8°F | 84.7°F | 86.2°F | 85.5°F | 84.9°F |
Marathon Key sea state in June
Chart comparing the height of waves in Marathon Key in June 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.
Marathon Key water temperature during other months:
You can also view information about water temperature for other months by clicking on the month button below
