August is Santorini at its absolute busiest — the hottest month of the year, the height of international tourist season, and home to one of Greece's biggest domestic travel dates, which adds a wave of Greek visitors on top of the usual summer crowd.
Weather
The hottest month of the year, with daytime highs regularly touching 30°C and little to no rain. Sea temperatures are at their warmest, and the meltemi wind provides some relief from the heat on breezier days.
August 15th: a genuinely different kind of busy
August 15th is the Dormition of the Virgin Mary, one of the biggest dates on the Greek calendar — a national holiday around which much of the country travels. In practice this means Santorini sees a surge of domestic Greek tourism layered onto the already-full international season around mid-August, with ferries, flights and accommodation booked especially far in advance around that date specifically.
Crowds and prices
At their annual peak, alongside July. Expect the busiest version of every popular spot — the Oia sunset crowd, the caldera-view restaurant waitlists, the Fira–Oia hike — and book everything as far ahead as you can, particularly around August 15th itself.
Our verdict
August offers the most reliably hot, dry summer weather of the year, but it's also the single most crowded and expensive month to visit — worth it for travellers locked into summer school-holiday dates, best avoided by anyone who can shift toward June or September instead.
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