Tampa Bay & Pinellas
St. Pete Beach Water Temperature
Boca Ciega Bay flats and Gulf-front structure below St. Pete.
That is right about average for this time of year, and holding steady over the last two weeks. The September average here is 86°F.
Updated Sunday, September 20 — sea-surface temperature modeled for St. Pete Beach by Open-Meteo.
Out in the open Gulf, NOAA buoy 42098 — 15 miles offshore — is reading 87°F. Deep water offshore runs cooler than the shallows in summer and warmer in winter, so it won't match the beach.
For swimming
Very warm
Bath-warm. Pleasant, though it stops being much relief from the heat of the day.
For fishing
Hot — fish the edges of the day
Early and late is the play. Through the middle of the day fish drop into deeper channels and passes where there's moving water and more oxygen.
The last two weeks
Daily average sea-surface temperature, °F.
St. Pete Beach water temperature by month
Averaged from 3 years of daily sea-surface temperature (2023–2025). The range column is the coolest and warmest daily average recorded in that month over the period — a guide to how much any given year can differ, not a record high and low.
| Month | Average | Range | Swimming |
|---|---|---|---|
| January | 61°F | 54–67°F | Bracing |
| February | 66°F | 60–74°F | Bracing |
| March | 71°F | 66–77°F | Cool but comfortable |
| April | 76°F | 73–80°F | Warm |
| May | 82°F | 77–87°F | Very warm |
| June | 86°F | 81–88°F | Very warm |
| July | 89°F | 86–90°F | Bath water |
| August | 89°F | 85–92°F | Bath water |
| Septembernow | 86°F | 83–88°F | Very warm |
| October | 79°F | 74–86°F | Warm |
| November | 73°F | 67–78°F | Cool but comfortable |
| December | 66°F | 62–71°F | Bracing |
Warmest on average in July at 89°F; coolest in January at 61°F.
The water at St. Pete Beach
St. Pete Beach separates the Gulf from Boca Ciega Bay, giving anglers grass flats and mangrove shoreline on the inside and open beach on the outside. Trout, redfish, and snook work the bay flats and bridges; Spanish mackerel and the occasional kingfish blitz bait along the beaches in spring and fall. The many bridges and passes here concentrate fish on moving water.
Pass-a-Grille & the Gulf
What moves the water temperature here
The Gulf shelf off this coast is shallow, which is why the water swings so much more between summer and winter than open ocean at the same latitude does. Shallow water heats fast and gives that heat up fast: a single strong winter cold front can pull the inshore bays several degrees down in a couple of days, while the beaches a mile offshore barely move. Wind direction matters too — a sustained offshore breeze can pull cooler water up from below and drop the beach temperature noticeably in a morning.
Inshore bays, canals and flats run warmer than the beach through the summer and colder through the winter, for the same reason. The reading above is for the open water at St. Pete Beach; expect the back bays to be a few degrees either side of it depending on the season.
Common questions
- What is the water temperature at St. Pete Beach right now?
- The water at St. Pete Beach is currently about 87°F (30°C). The September average here is 86°F.
- Is the water warm enough to swim at St. Pete Beach in September?
- September averages 86°F at St. Pete Beach, which most people would call very warm. Bath-warm. Pleasant, though it stops being much relief from the heat of the day.
- When is the water warmest at St. Pete Beach?
- July is the warmest month on average at 89°F, and January the coolest at 61°F. 7 months of the year average 75°F or above.
- Why does the water temperature change so quickly here?
- The Gulf shelf off this coast is shallow, so it heats and cools far faster than deep open ocean. A strong winter cold front can pull the inshore water down several degrees in a couple of days, and a sustained offshore wind can drop beach temperatures in a single morning by pulling cooler water up from below.