Sea TemperaturesKey West Sea Temperature
Looking to find out what the sea water temperature in Key West is for today and the next few days? Below are data and charts that will give you information about sea temperatures in Key West and nearby locations.
Water temperature in Key West right now
Below is the current sea temperature for Key West, United States on January 15, 2026.
Today
21.83° C
71.3° F
Yesterday
22.2° C
71.96° F
A week ago
22.35° C
72.23° F
Water at this temperature is very pleasant to swim in and if you tend to wear a wetsuit when swimming, you might consider removing it now to avoid the body overheating.
The average sea temperature for Key West on January 15 over the last 10 years is 21.83° C (71.3° F), with a low temperature of 20.38° C (68.68° F) and a high of 23.51° C (74.32° F).
Analysis and forecast for Key West water temperatures
The water temperature in Key West today is the same as the average temperature of 21.83° C (71.3° F) and the temperature on this day last year was 21.83° C (71.3° F).
The chart and table below shows the change in water temperature in Key West over the last 30 days:
| Date | Temperature (Celsius) | Temperature (Fahrenheit) |
|---|---|---|
| January 15 | 21.83° C | 71.3° F |
| January 14 | 22.2° C | 71.96° F |
| January 13 | 22.24° C | 72.04° F |
| January 12 | 22.21° C | 71.98° F |
| January 11 | 22.16° C | 71.88° F |
| January 10 | 22.19° C | 71.93° F |
| January 9 | 22.25° C | 72.05° F |
| January 8 | 22.35° C | 72.23° F |
| January 7 | 22.52° C | 72.53° F |
| January 6 | 22.46° C | 72.44° F |
| January 5 | 22.66° C | 72.78° F |
| January 4 | 22.76° C | 72.97° F |
| January 3 | 22.74° C | 72.94° F |
| January 2 | 22.7° C | 72.85° F |
| January 1 | 22.77° C | 72.98° F |
| December 31 | 22.89° C | 73.21° F |
| December 30 | 22.82° C | 73.08° F |
| December 29 | 22.79° C | 73.03° F |
| December 28 | 22.67° C | 72.81° F |
| December 27 | 22.66° C | 72.79° F |
| December 26 | 22.74° C | 72.93° F |
| December 25 | 22.89° C | 73.21° F |
| December 24 | 22.93° C | 73.27° F |
| December 23 | 23.05° C | 73.48° F |
| December 22 | 23.18° C | 73.73° F |
| December 21 | 23.3° C | 73.94° F |
| December 20 | 23.27° C | 73.89° F |
| December 19 | 23.39° C | 74.1° F |
| December 18 | 23.52° C | 74.34° F |
| December 17 | 23.53° C | 74.35° F |
The actual nearshore temperatures may vary by several degrees and this can also be heavily affected by weather. Strong winds can cause cold, deep waters to replace the surface waters that had been warmed by the sun, and heavy rain can also reduce the temperature of the sea surface temperature as well.
Water temperature in Key West by month
The chart below shows the monthly average water temperature in Key West.
For more detailed information on how the sea temperature in Key West changes for each month of the year, choose from the months below.
Key West map and nearby water temperatures
Locations near Key West
Why measure sea surface temperatures (SST) in Key West?
The ocean covers about 71% of the Earth's surface, and scientists record the sea surface temperature (SST) of locations such as Key West because they want to understand and learn how the ocean communicates with the atmosphere of Earth.
SST is one measure that provides information on the global climate, and it can be used to predict the weather in Key West as well as atmospheric model simulations and to study marine ecosystems in the area.
Data source and citation
Raw data for the calculations made to find the sea surface temperature in Key West comes from the National Oceanic and Atmospheric Administration (NOAA) and their 1/4° daily Optimum Interpolation Sea Surface Temperature.
The water temperature data is constructed by combining observations from different platforms (satellites, ships, buoys, and Argo floats) on a regular global grid. A spatially complete sea surface temperature map is then built by interpolating to fill in gaps in the data.
If you'd like to use any of the information above in the format it is presented, please use the citation tool below.