Alabama Coast
Dauphin Island Water Temperature
A barrier island at the mouth of Mobile Bay, and a famous spring bird stopover.
That is about 7°F warmer than average for this time of year, and cooling over the last two weeks. The October average here is 77°F.
Updated Saturday, October 3 — sea-surface temperature modeled for Dauphin Island by Open-Meteo.
Out in the open Gulf, NOAA buoy 42012 — 36 miles offshore — is reading 85°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.
Dauphin Island 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 | 56°F | 49–62°F | Cold |
| February | 60°F | 56–68°F | Bracing |
| March | 66°F | 61–73°F | Bracing |
| April | 72°F | 67–80°F | Cool but comfortable |
| May | 80°F | 72–84°F | Warm |
| June | 85°F | 81–90°F | Very warm |
| July | 88°F | 87–90°F | Bath water |
| August | 89°F | 86–91°F | Bath water |
| September | 85°F | 81–89°F | Very warm |
| Octobernow | 77°F | 71–84°F | Warm |
| November | 70°F | 63–77°F | Cool but comfortable |
| December | 61°F | 55–65°F | Bracing |
Warmest on average in August at 89°F; coolest in January at 56°F.
The water at Dauphin Island
Dauphin Island closes off the west side of Mobile Bay's mouth, with the pass at one end and the ferry across to Fort Morgan at the other. Fishing runs the length of it — trout and redfish in the sound and around the pass, pompano and whiting in the surf, flounder along the sandy edges — and deeper water offshore puts snapper and mackerel within a reasonable run. The island is also one of the best-known migration stopovers in North America: songbirds crossing the Gulf in spring make landfall right here, and a passing front can drop exhausted migrants into the island's woods by the thousand. Birders watch April weather more closely than anglers do.
the island, the pass & 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 Dauphin Island; 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 Dauphin Island right now?
- The water at Dauphin Island is currently about 84°F (29°C). The October average here is 77°F.
- Is the water warm enough to swim at Dauphin Island in October?
- October averages 77°F at Dauphin Island, which most people would call warm. About as good as it gets — warm enough to stay in for hours without getting chilled.
- When is the water warmest at Dauphin Island?
- August is the warmest month on average at 89°F, and January the coolest at 56°F. 6 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.