July and August are peak season — beaches are crowded, parties run every night, and prices are at their highest. June and September are the sweet spot: warm enough to swim, less frantic, and prices noticeably lower. May and October are quieter still but the sea can be cool and many businesses close.
The meltemi, a strong dry northerly wind, blows reliably from mid-July through August. It can make the north coast rough but keeps temperatures bearable. South-facing beaches are sheltered from it. Outside the June–September window, most restaurants, bars, and beach clubs close and the island reverts to a much quieter, more local character.