Amelia Island water temperature in May
Key facts
The Atlantic off Amelia Island averages 77.7°F in May — warm. Warm enough to stay in as long as you like. That is 5.1°F above the island’s annual average of 72.6°F, and 6.5°F up on April.
- Average daily high to low
- Ocean temperature
May in the water
May is the crossover. By the end of the month the ocean is comfortable for most people without neoprene, and it stays that way for five months. Sea turtle nesting opens on 1 May, so the beach itself comes with rules from here to the end of October.
At 77.7°F the sea is 5.1°F above the island’s annual average of 72.6°F. The air reaches 83.9°F in May, a gap of 6.2°F, noticeable for the first thirty seconds and then gone.
What to wear
Nothing needed. A rash vest is for sun, not warmth.
Where this number comes from
77.7°F is the mean of every hourly reading for May 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 May 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.
May against the months either side
| April | May | June | |
|---|---|---|---|
| Sea temperature | 71.2°F | 77.7°F | 80.8°F |
| Our reading | Comfortable | Warm | Warm |
| Air high | 77.4°F | 83.9°F | 88.3°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 May
Sea turtle nesting season runs 1 May to 31 October under FWC rules, and May 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.
Next and previous months
Planning a May beach day
Part of Amelia Island water temperature by month.
Frequently asked questions
- What is the water temperature at Amelia Island in May?
- The ocean averages 77.7°F (25.4°C) in May, 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 May?
- Warm at 77.7°F. Warm enough to stay in as long as you like.
- Do you need a wetsuit at Amelia Island in May?
- Nothing needed. A rash vest is for sun, not warmth.