Average Ocean Water Temperatures at Key West
The table below lists typical water temperatures for each month of the year in the ocean off Key West in Florida.
The temperatures, given in both degrees Fahrenheit and degrees Celsius, are long-term averages.
The water at Key West is warm enough for swimming all year round.
The ocean reaches its warmest point of the year in July and August when the temperature averages 87 degrees Fahrenheit (31 degrees Celsius).
The coolest month is January, when the temperature is usually around 69 °F (21 °C).
| Period | °F | °C |
|---|---|---|
| January | 69 | 21 |
| February | 70 | 21 |
| March | 75 | 24 |
| April | 78 | 26 |
| May | 82 | 28 |
| June | 85 | 29 |
| July | 87 | 31 |
| August | 87 | 31 |
| September | 86 | 30 |
| October | 82 | 28 |
| November | 76 | 24 |
| December | 72 | 22 |
| Annual Average | 79 | 26 |
Reference
National Oceanographic Data Center. NODC Coastal Water Temperature Guide (CWTG).