Amelia Island water temperature in July

By Kaden Ewald, Editor Last updated How we verify

Key facts

The Atlantic off Amelia Island averages 82.7°F in July — bath-warm. No cooling effect at all — shade and water matter more than the sea. That is 10.1°F above the island’s annual average of 72.6°F, and 1.9°F up on June.

July in context: Amelia Island climate normals July on Amelia Island: average high 90.7°F, average low 74.9°F, ocean 82.7°F, 4.96 inches of rain across about 9.3 wet days. Shown against all twelve months of the 1991–2020 normals. 40° 50° 60° 70° 80° 90° 100° Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 90.7° air · 82.7° sea °F rain
  • Average daily high to low
  • Ocean temperature
Air temperature and rainfall: NOAA NCEI 1991–2020 monthly normals, station FERNANDINA BEACH, FL (USC00082944), on the island. Ocean temperature: Mean of hourly water-temperature readings for 2023–2025 at NOAA CO-OPS station 8720218, Mayport (Bar Pilots Dock), about 30 km south. The Fernandina Beach station has no water-temperature sensor.

July in the water

July water gives you very little relief from a ninety-degree afternoon, which is the point at which shade matters more than the sea. On a low-tide morning the shallows over the sandbars are warmer still.

At 82.7°F the sea is 10.1°F above the island’s annual average of 72.6°F. The air reaches 90.7°F in July, a gap of 8°F, noticeable for the first thirty seconds and then gone.

What to wear

Nothing needed, and neoprene would be actively unpleasant.

Where this number comes from

82.7°F is the mean of every hourly reading for July across 2023, 2024 and 2025 at NOAA CO-OPS station 8720218, Mayport (Bar Pilots Dock), FL — about 30 km south of the island. The Fernandina Beach station on the island has no water-temperature sensor, so no on-island long record exists to average. We would rather say that plainly than publish an on-island figure we cannot support.

A monthly mean is not a forecast. The real ocean in any given July week moves several degrees around this figure, and a hard south-westerly can pull colder water up onto the shelf in a day. For the reading right now, the offshore waverider buoy 41112 (Offshore Fernandina Beach, FL, 17 km ENE) reports water temperature alongside wave height — that is what feeds our surf report and beach conditions.

July against the months either side

June July August
Sea temperature 80.8°F 82.7°F 84.6°F
Our reading Warm Bath-warm Bath-warm
Air high 88.3°F 90.7°F 89.5°F

The annual mean is 72.6°F, and the sea lags the air by about two months in both directions — see water temperature by month for why that lag matters more than the raw number.

One rule for the beach in July

Sea turtle nesting season runs 1 May to 31 October under FWC rules, and July falls inside it. Fill in every hole, take all gear off the beach overnight, keep lights off the sand and stay well clear of marked nests. See sea turtles on Amelia Island.

Part of Amelia Island water temperature by month.

Frequently asked questions

What is the water temperature at Amelia Island in July?
The ocean averages 82.7°F (28.2°C) in July, from three years of hourly NOAA readings at the nearest sensor with a long record — station 8720218, 30 km south of the island. A given week moves several degrees around that.
Can you swim at Amelia Island in July?
Bath-warm at 82.7°F. No cooling effect at all — shade and water matter more than the sea.
Do you need a wetsuit at Amelia Island in July?
Nothing needed, and neoprene would be actively unpleasant.