When is the best time to swim in the Greek Islands?

The Greek Islands is warmest during Late May – mid October, when the Aegean Sea averages 26°C. There are typically 5 months a year when the sea sits above 22°C.

How warm is the sea in the Greek Islands in August?

The Aegean Sea off the Greek Islands averages 26.0°C in August.

Greek Islands sea temperature

Greek Islands

Cyclades, Dodecanese and Ionian beaches with 26°C summer water.

Sea

Aegean Sea

Avg sea temp now

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Best months

Late May – mid October

Greek island water is famously warm and clear. Cyclades (Mykonos, Naxos, Paros) and Dodecanese (Rhodes, Kos) sit in the Aegean, while the Ionian (Corfu, Zakynthos) faces Italy and stays a degree or two warmer in shoulder season. August averages 26°C; swimming season runs comfortably from late May to mid-October.

Best time to swim in Greek Islands

The sea in Greek Islands peaks in August, when the water averages around 26°C.

The main swimming season runs from May – November, when surface temperatures stay comfortable for extended sessions.

On average, 7 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.

Shoulder months like April and December are noticeably cooler but often quieter, with fewer crowds and steadier weather.

Outside peak season the water drops toward 17°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable.

The coldest month is typically February at around 15°C, when cold-water swimmers dominate the coast.

Greek Islands sea temperature history

Long-term climatology for Greek Islands shows an annual mean sea temperature of 20°C, ranging from 15°C in winter to 26°C at the summer peak.

The seasonal swing is roughly 11°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.

Recent decades have trended slightly warmer at Greek Islands, in line with regional sea-surface temperature records for the wider basin.

Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.

Jan

16°C

Feb

15°C

Mar

15°C

Apr

17°C

May

20°C

Jun

23°C

Jul

25°C

Aug

26°C

Sep

25°C

Oct

22°C

Nov

20°C

Dec

17°C

Values are area averages; individual beaches vary by exposure and depth.

Greek Islands sea temperature: frequently asked questions

What is the warmest month to swim in Greek Islands?

August is the warmest month in Greek Islands, when the sea averages about 26°C. Late-season warmth often persists a few weeks after peak.

When is the sea coldest in Greek Islands?

The coldest month in Greek Islands is typically February, when the water averages around 15°C. Cold-water swimmers and surfers dominate this period.

When can you swim in Greek Islands without a wetsuit?

The main swimming season in Greek Islands runs from May – November — about 7 months a year when the sea sits above 20°C, the level most swimmers describe as pleasant without a wetsuit.

Do I need a wetsuit in Greek Islands?

Outside peak summer the water in Greek Islands drops toward 17°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable. In peak months most swimmers go without.

What is the average sea temperature in Greek Islands?

The long-term annual mean sea temperature in Greek Islands is about 20°C, based on multi-decadal climatology of the surrounding waters.

How do I check the current sea temperature in Greek Islands?

The live reading at the top of this page shows the current sea temperature in Greek Islands, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.

Greek Islands

Best time to swim in Greek Islands

Greek Islands sea temperature history

Greek Islands sea temperature: frequently asked questions

Beaches in the Greek Islands

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