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Is it too cold to swim in Siesta Key?
The latest NASA JPL satellite analysis, dated November 3, 2026, gives 79°F (25.9°C) at the nearest water pixel. That is warm water.
Above 77°F, the temperature below which cold water starts to affect breathing control. Temperature is only one factor: check rip current and surf alerts, and swim near lifeguards.
How cold is too cold to swim?Water temperature through the year
Average water temperature by month, satellite 2016–2025. Warmest in August.
Average ocean temperature by month
| Month | Average | Coldest year | Warmest year |
|---|---|---|---|
| January | 65°F | 61°F | 67°F |
| February | 66°F | 62°F | 69°F |
| March | 70°F | 68°F | 74°F |
| April | 75°F | 74°F | 79°F |
| May | 80°F | 77°F | 82°F |
| June | 85°F | 84°F | 86°F |
| July | 87°F | 85°F | 88°F |
| August | 87°F | 86°F | 89°F |
| September | 86°F | 85°F | 87°F |
| October | 81°F | 78°F | 83°F |
| November | 74°F | 72°F | 76°F |
| December | 68°F | 66°F | 70°F |
Other water temperature readings nearby
| Source | Water | Distance | Updated |
|---|---|---|---|
| Venice Inlet at Crow'S Nest Marina at Venice FL bay gauge | 77°F | 12 mi | 2 h ago |
| Donna Bay at Highway 41 at Nokomis FL bay gauge | 78°F | 12 mi | 2 h ago |
Water temperatures at nearby beaches
Frequently asked questions
Is it too cold to swim in Siesta Key?
The latest NASA JPL satellite analysis, dated November 3, 2026, gives 79°F (25.9°C) at the nearest water pixel. That is warm water. Above 77°F, the temperature below which cold water starts to affect breathing control. Temperature is only one factor: check rip current and surf alerts, and swim near lifeguards. How cold is too cold?
When is the water warmest at Siesta Key?
Based on satellite data from 2016 to 2025, the water is warmest in August (average 87°F) and coldest in January (average 65°F).
Where does this water temperature come from?
We show NASA JPL’s daily MUR satellite analysis for the nearest water, about 0.6 mi away, when no suitable current in-water sensor is available. Satellite values are typically a degree or two cooler than afternoon readings at the shore. Satellite vs. buoy temperatures.
Sources: NASA JPL MUR satellite analysis; U.S. Geological Survey; forecast and alerts from the National Weather Service. Readings are provisional. All Florida water temperatures · Methodology