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.
Greek Islands
Cyclades, Dodecanese and Ionian beaches with 26°C summer water.
Sea
Aegean Sea
Avg sea temp now
24.9°C
Best months
Late May – 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.
Beaches in the Greek Islands
Ranked by current live sea temperature.
- 1ManganariIos, Greece25.7°C
- 2KathismaLefkada, Greece25.7°C
- 3PelekasCorfu, Greece25.7°C
- 4Porto TimoniCorfu, Greece25.6°C
- 5Kalafatis BeachMykonos, Greece25.6°C
- 6Pyrgaki BeachNaxos, Greece25.6°C
- 7Lentas BeachLentas, Greece25.6°C
- 8KolymbithresParos, Greece25.5°C
- 9Mylos BeachLefkada, Greece25.5°C
- 10Pounda BeachParos, Greece25.5°C
- 11Kedrodasos BeachElafonissi, Greece25.5°C
- 12Kommos BeachPitsidia, Greece25.5°C
- 13Elounda BeachElounda, Greece25.5°C
- 14Agia AnnaNaxos, Greece25.4°C
- 15KamariSantorini, Greece25.4°C
- 16Vrika BeachAntipaxos, Greece25.4°C
- 17Skala BeachKefalonia, Greece25.4°C
- 18Stavros BeachChania, Greece25.4°C
- 19Voulisma BeachAgios Nikolaos, Greece25.4°C
- 20Marathi BeachChania, Greece25.4°C
- 21Georgioupoli BeachGeorgioupoli, Greece25.4°C
- 22VoutoumiPaxos, Greece25.3°C
- 23Antisamos BeachKefalonia, Greece25.3°C
- 24Platis GialosMykonos, Greece25.3°C
- 25Chrissi Island BeachIerapetra, Greece25.3°C
- 26Manganari BeachIos, Greece25.3°C
- 27Analipsi BeachAnalipsi, Greece25.3°C
- 28Xerokambos BeachXerokambos, Greece25.3°C
- 29PaleokastritsaCorfu, Greece25.2°C
- 30PaliochoriMilos, Greece25.2°C
- 31Elafonissi BeachElafonissi, Greece25.2°C
- 32Plakias BeachPlakias, Greece25.2°C
- 33EgremniLefkada, Greece25.1°C
- 34Tsilivi BeachZakynthos, Greece25.1°C
- 35Agrari BeachMykonos, Greece25.1°C
- 36Loutraki CreteChania, Greece25.1°C
- 37Souda BeachPlakias, Greece25.1°C
- 38PlakaNaxos, Greece25.0°C
- 39Red BeachSantorini, Greece25.0°C
- 40AntisamosSami, Greece25.0°C
- 41Glyfada CorfuCorfu, Greece25.0°C
- 42Marcello BeachParos, Greece25.0°C
- 43Triopetra BeachRethymno, Greece25.0°C
- 44Chrysi IslandIerapetra, Greece25.0°C
- 45Kalives BeachKalives, Greece25.0°C
- 46Sarakiniko Beach CreteIerapetra, Greece25.0°C
- 47ParagaMykonos, Greece24.9°C
- 48SarakinikoMilos, Greece24.9°C
- 49GlyfadaCorfu, Greece24.9°C
- 50Porto KatsikiLefkada, Greece24.9°C
- 51VoutoumiAntipaxos, Greece24.9°C
- 52Frangokastello BeachFrangokastello, Greece24.9°C
- 53Ammoudi Beach PlakiasPlakias, Greece24.9°C
- 54Kalathas BeachChania, Greece24.9°C
- 55Rethymno BeachRethymno, Greece24.9°C
- 56Voulismeni BeachIerapetra, Greece24.9°C
- 57FalassarnaChania, Greece24.8°C
- 58MatalaHeraklion, Greece24.8°C
- 59Anthony Quinn BayRhodes, Greece24.8°C
- 60Panormos BeachRethymno, Greece24.8°C
- 61Xerokampos BeachSitia, Greece24.8°C
- 62MylopotasIos, Greece24.7°C
- 63Super ParadiseMykonos, Greece24.7°C
- 64Elia BeachMykonos, Greece24.7°C
- 65St Paul's BayLindos, Greece24.7°C
- 66Xi BeachKefalonia, Greece24.7°C
- 67Seitan LimaniaChania, Greece24.7°C
- 68Almyros BeachAgios Nikolaos, Greece24.7°C
- 69Damnoni BeachPlakias, Greece24.7°C
- 70Agia Marina BeachAgia Marina, Greece24.7°C
- 71Platanias BeachPlatanias, Greece24.7°C
- 72Almyrida BeachAlmyrida, Greece24.7°C
- 73Amoudara BeachHeraklion, Greece24.7°C
- 74Malia BeachMalia, Greece24.7°C
- 75ElafonisiChania, Greece24.6°C
- 76BalosKissamos, Greece24.6°C
- 77PerissaSantorini, Greece24.6°C
- 78FiriplakaMilos, Greece24.6°C
- 79TsigradoMilos, Greece24.6°C
- 80TsambikaRhodes, Greece24.6°C
- 81Egremni BeachLefkada, Greece24.6°C
- 82Banana BeachZakynthos, Greece24.6°C
- 83Issos BeachCorfu, Greece24.6°C
- 84Marathi BeachChania, Greece24.6°C
- 85Panormo BeachPanormo, Greece24.6°C
- 86Stalis BeachStalis, Greece24.6°C
- 87Hersonissos BeachHersonissos, Greece24.6°C
- 88Seitan LimaniaChania, Greece24.5°C
- 89PreveliRethymno, Greece24.5°C
- 90PrasonisiRhodes, Greece24.5°C
- 91Mikri ViglaNaxos, Greece24.5°C
- 92Gerakas BeachZakynthos, Greece24.5°C
- 93Kalo LivadiMykonos, Greece24.5°C
- 94Spinalonga BeachElounda, Greece24.5°C
- 95Voulisma BeachIstron, Greece24.5°C
- 96StavrosChania, Greece24.4°C
- 97Golden BeachParos, Greece24.4°C
- 98Lindos BayLindos, Greece24.4°C
- 99Alyko BeachNaxos, Greece24.4°C
- 100Monolithos BeachSantorini, Greece24.4°C
- 101Komos BeachHeraklion, Greece24.4°C
- 102Agios Nikolaos BeachAgios Nikolaos, Greece24.4°C
- 103Sitia BeachSitia, Greece24.4°C
- 104VaiSitia, Greece24.3°C
- 105Agios ProkopiosNaxos, Greece24.3°C
- 106Bali BeachBali, Greece24.3°C
- 107Kokkini Hani BeachKokkini Hani, Greece24.3°C
Swimming in the Greek Islands — FAQ
How warm is the sea in the Greek Islands in September?
The Aegean Sea off the Greek Islands averages about 25.0°C in September, based on long-term monthly averages for this coast.
When is the best time to swim in the Greek Islands?
The Greek Islands is warmest in August (around 26.0°C) and coldest in February (around 15.0°C). There are typically 5 months a year when the water sits above 22°C.
What is the average yearly sea temperature in the Greek Islands?
Across all twelve months, the sea in the Greek Islands averages about 20.1°C.
Do you need a wetsuit to swim in the Greek Islands?
In peak season (around August, ~26.0°C) most swimmers are comfortable without a wetsuit. Outside summer, when the water drops toward 15.0°C, a 3/2mm to 5/4mm wetsuit is recommended.