Key West Sea Water Temperature
The southernmost point in continental US, celebrated for crystal-clear warm shallows. Today's reading, 7-day forecast, and monthly averages below.
Key West water temperature
Very warm bath-like water. Zero chill, exceptional for relaxation and snorkeling.
7-Day Water Temperature Forecast
Key West Monthly Water Temperature Averages
Historical monthly climatology. The warmest water in Key West occurs inApr, May, Jun, Jul, Aug, Sep, Oct, Nov — peaking at30.8°C (87.4°F) in August.
Year-Round Water Temperature Curve (°C / °F)
Hover a bar for detailsFull 12-month data table — min / avg / max & swimming comfort
| Month | Min Water Temp | Average Water Temp | Max Water Temp | Swimming Comfort |
|---|---|---|---|---|
| January | 20.8°C | 22.4°C | 23.9°C | Comfortable (20°C – 24°C) |
| February | 21.2°C | 22.8°C | 24.4°C | Comfortable (20°C – 24°C) |
| March | 22.5°C | 24.1°C | 25.8°C | Warm & Ideal (24°C – 28°C) |
| April | 24.7°C | 26.2°C | 27.6°C | Warm & Ideal (24°C – 28°C) |
| May | 26.8°C | 28°C | 29.3°C | Tropical Warm (> 28°C) |
| June | 28.5°C | 29.7°C | 30.8°C | Tropical Warm (> 28°C) |
| July | 29.4°C | 30.5°C | 31.5°C | Tropical Warm (> 28°C) |
| August | 29.8°C | 30.8°C | 31.8°C | Tropical Warm (> 28°C) |
| SeptemberCurrent | 29.1°C | 30.1°C | 31.2°C | Tropical Warm (> 28°C) |
| October | 27.2°C | 28.4°C | 29.7°C | Tropical Warm (> 28°C) |
| November | 24.7°C | 26°C | 27.4°C | Warm & Ideal (24°C – 28°C) |
| December | 22.2°C | 23.7°C | 25.1°C | Comfortable (20°C – 24°C) |
Swimming FAQs for Key West
Is the sea warm enough to swim in Key West today?
Typical sea surface temperature in Key West this time of year is 30.1°C (86.2°F) — classified as Tropical Warm (> 28°C). Very warm bath-like water. Zero chill, exceptional for relaxation and snorkeling. Live readings load automatically.
What are the warmest months for swimming in Key West?
The highest water temperatures in Key West typically occur duringApr, May, Jun, Jul, Aug, Sep, Oct, Nov, when monthly averages reach peak seasonal levels.
What is the typical water temperature in Key West in September?
Historically in September, water temperatures in Key West average around30.1°C (86.2°F), fluctuating between a recorded minimum of 29.1°C and a maximum of 31.2°C.