Best Time to Visit Santorini
Short answer: late May to June, or September to mid-October.
In those months the sea is warm enough to swim, the days are long, the light over the caldera is clear, and the hotels haven't yet gone to full summer rates. September is the pick for swimming, because the water has had all summer to warm up.
July and August are peak season. Hotel prices peak too, cruise ships are at their busiest, Oia is packed every evening, and the buses fill up. The heat is usually bearable, since there's almost always a breeze, but that breeze has a name. The meltemi is a strong, dry north wind that blows across the Aegean in high summer, sometimes for days. It keeps things cool, whips sand across the east coast beaches, and can delay or cancel smaller ferries and boat trips.
April and late October are mild and much quieter, though the sea is cold and some boat trips don't run yet. Easter, which follows the Orthodox calendar, is busy with Greek visitors and a lovely time to be in Pyrgos, where the village is lit with small fires and lamps on Good Friday.
The winter question
From November to March, most caldera hotels and many restaurants close. Those that stay open are cheap, the villages are calm and you'll have the Fira to Oia path mostly to yourself. It can also be grey, wet and windy, and ferry connections are fewer. It suits a short, quiet stay built around walking and wine, not a beach holiday.
Month by month
- April and May: warm days, cool sea, flowers on the hillsides.
- June: summer weather, crowds building but not yet at full volume.
- July and August: hot, windy, busiest and most expensive.
- September: warmest sea, still busy early in the month.
- October: mild, quieter, some places closing towards the end.
- November to March: off season, limited services, lowest prices.
One more thing to check before you book: the cruise schedule for your dates. Fewer ships in port means a calmer Fira and Oia.