This data the coastal Florida Keys ocean water temperature today, tomorrow and the upcoming days. Besides, you can also get information about the weather and surf forecast, as well as the data on sunrise / sunset and moonrise / moonset at a given point on any given day.
Water temperature in Florida Keys today is 86°F. Based on our historical data over a period of ten years, the warmest water in this day in the Atlantic Ocean near Florida Keys was recorded in 2024 and was 88°F, and the coldest was recorded in 2013 at 83.8°F. Sea water temperature in Florida Keys is expected to drop to 84.7°F in the next 10 days. September average water temperature in Florida Keys is 85.8°F, the minimum temperature is 82.8°F, and the maximum is 88.9°F.
The swimming season in Florida Keys lasts from January to December, twelve months per year! During those months, Florida Keys water temperature does not drop below 68°F and therefore suitable for comfortable swimming. The average water temperature in Florida Keys in winter reaches 75.4°F, in spring 78.8°F, in summer the average temperature rises to 85.8°F, and in autumn it is 82.8°F.
September 21, 2025 |
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today temp |
86°F |
September 20, 2025 |
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yesterday temp |
86°F |
The ocean salinity in Florida Keys is 36.39‰, and the average salinity of the World Ocean is 35‰.
Another important indicators for a comfortable holiday on the beach are the presence and height of the waves, as well as the speed and direction of the wind. Please find below data on the swell size for Florida Keys. We calculate the swell size based on the mean wave height (trough to crest) of each third highest wave. For more information on surf forecasts for the next ten days, please visit sea state forecast Florida Keys. Data in table shown for September 21, 2025, time in GMT 0 format (you can change the time zone on the sea state forecast page)
0-3 h | 3-6 h | 6-9 h | 9-12 h |
---|---|---|---|
1' 10" | 1' 10" | 1' 7" | 1' 2" |
0.55 m | 0.57 m | 0.47 m | 0.36 m |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
---|---|---|---|
0' 11" | 1' 0" | 1' 2" | 1' 3" |
0.28 m | 0.31 m | 0.36 m | 0.37 m |
Data in a table show Florida Keys temperature today (September 21, 2025). For more information and forecast for a few days, go to the weather forecast Florida Keys.
0-3 h | 3-6 h | 6-9 h | 9-12 h |
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82.6°F | 81.9°F | 81.5°F | 81.7°F |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
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83.3°F | 83.8°F | 83.1°F | 83.1°F |
You may also be interested in other sections of our site for Florida Keys: Sunrise and Sunset, Tides
These figures shows the average, minimum and maximum monthly sea temperature in Florida Keys. In addition to the table values, the graph below displays of changes average surface temperature during the year. Values are calculated based on the data over the past 10 years. Using them, you can check the water temperature in Florida Keys on any day of this period that interests you. Click on the month link and you will see a table for each day, or alternatively you can view the temperature curve of the month and select 2 different years you want to compare, either in a table or as a curve
Month | Avr | Min | Max | |
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January | 74.7°F | 68.9°F | 80.1°F | warm |
Ocean water temperature in Florida Keys in January | ||||
February | 74.7°F | 69.1°F | 79.2°F | warm |
Ocean water temperature in Florida Keys in February | ||||
March | 76.1°F | 70.5°F | 80.4°F | warm |
Ocean water temperature in Florida Keys in March | ||||
April | 78.6°F | 73.8°F | 84°F | hot |
Ocean water temperature in Florida Keys in April | ||||
May | 81.5°F | 77.4°F | 88.2°F | hot |
Ocean water temperature in Florida Keys in May | ||||
June | 84.6°F | 79.5°F | 88°F | hot |
Ocean water temperature in Florida Keys in June | ||||
July | 86.2°F | 82.4°F | 90°F | hot |
Ocean water temperature in Florida Keys in July | ||||
August | 86.7°F | 83.3°F | 90°F | hot |
Ocean water temperature in Florida Keys in August | ||||
September | 85.8°F | 82.8°F | 88.9°F | hot |
Ocean water temperature in Florida Keys in September | ||||
October | 83.1°F | 78.8°F | 86.5°F | hot |
Ocean water temperature in Florida Keys in October | ||||
November | 79.5°F | 75.4°F | 83.7°F | hot |
Ocean water temperature in Florida Keys in November | ||||
December | 76.8°F | 71.1°F | 80.6°F | warm |
Ocean water temperature in Florida Keys in December |