Water temperature in Key West (FL) in August
Is it warm enough to swim in Key West in August? Average water temperature in Key West in August is 86.7°F and therefore suitable for comfortable swimming. The warmest sea in Key West in August is 90°F, and the coldest is 83.3°F. Average high air temperature in Key West in August is 89°F, and average low temperature is 80°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 August 2025, 2024
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 August.
You can choose any other years:
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| August 1 | 87.6°F | 87.8°F | 85.1°F | 88°F |
| August 2 | 87.3°F | 88°F | 85.3°F | 88.2°F |
| August 3 | 87.6°F | 87.6°F | 85.1°F | 88.5°F |
| August 4 | 87.8°F | 87.3°F | 85.6°F | 88°F |
| August 5 | 88.3°F | 86.7°F | 85.1°F | 88.3°F |
| August 6 | 87.4°F | 86.2°F | 85.5°F | 88.5°F |
| August 7 | 87.6°F | 86.7°F | 85.3°F | 88.2°F |
| August 8 | 87.6°F | 87.1°F | 85.5°F | 89.1°F |
| August 9 | 87.4°F | 87.1°F | 85.8°F | 89.6°F |
| August 10 | 87.1°F | 88°F | 85.5°F | 89.6°F |
| August 11 | 86.9°F | 87.4°F | 85.1°F | 90°F |
| August 12 | 87.1°F | 87.6°F | 85.1°F | 89.4°F |
| August 13 | 86.2°F | 88.7°F | 85.5°F | 89.1°F |
| August 14 | 86.7°F | 88°F | 85.3°F | 89.2°F |
| August 15 | 87.8°F | 88°F | 85.5°F | 89.4°F |
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| August 16 | 87.6°F | 88°F | 85.3°F | 88.9°F |
| August 17 | 88.2°F | 88.2°F | 85.6°F | 88.7°F |
| August 18 | 88.5°F | 87.4°F | 85.6°F | 89.1°F |
| August 19 | 88.5°F | 87.4°F | 85.6°F | 88.7°F |
| August 20 | 88.2°F | 87.4°F | 85.6°F | 88.5°F |
| August 21 | 88.3°F | 88°F | 85.3°F | 88.3°F |
| August 22 | 89.2°F | 87.4°F | 85.1°F | 89.2°F |
| August 23 | 88.7°F | 88°F | 84.9°F | 88.7°F |
| August 24 | 88.7°F | 88°F | 84.9°F | 88.7°F |
| August 25 | 88.5°F | 87.3°F | 84.7°F | 88.5°F |
| August 26 | 89.8°F | 87.3°F | 84.4°F | 89.8°F |
| August 27 | 89.6°F | 87.1°F | 84°F | 89.6°F |
| August 28 | 88.9°F | 86.9°F | 83.3°F | 88.9°F |
| August 29 | 88.7°F | 86.5°F | 83.8°F | 88.7°F |
| August 30 | 88.5°F | 86.5°F | 84°F | 88.5°F |
| August 31 | 88.7°F | 86.7°F | 83.5°F | 88.7°F |
Average water temperature in Key West in August over a decade
| 2016 | 2017 | 2018 | 2019 | 2020 |
| 86.2°F | 86.4°F | 86.2°F | 86.9°F | 86.5°F |
| 2021 | 2022 | 2023 | 2024 | 2025 |
| 86.4°F | 86.7°F | 88.3°F | 87.4°F | 87.6°F |
Key West sea state in August
Chart comparing the height of waves in Key West 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 Key West in August
This data display average monthly climate indicators in Key West 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 temperature89°F
- Average LOW temperature80°F
- Average humidity
73 - Average rainfall days14 days
- Average rainfall124mm/4.9''
- Average daylight13h
- Average sunshine9.9h
- Average UV index11
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
