The best time to visit Athens is April to June and September to October, when temperatures are warm but not brutal, crowds are manageable, and outdoor sightseeing is genuinely comfortable.
Spring (April–May): Daytime highs of 18–24°C, wildflowers on the hillsides, low hotel rates, and the Easter celebrations — one of the most atmospheric times in the Greek calendar. Ideal for walkers and history lovers.
Early summer (June): Still comfortable in the first half (mid-20s°C) before the full July–August heat arrives. Longer days mean more sightseeing time and the Athens Epidaurus Festival (outdoor theatre and concerts) begins.
High summer (July–August): Peak season with temperatures regularly reaching 35–40°C. The Acropolis becomes punishing by mid-morning. Crowds and prices peak. Worth it only if you plan to combine with islands and can sightsee early and late.
Autumn (September–October): Arguably the best time overall — sea temperatures still warm enough for a coastal day trip or island extension, air temperatures drop to 22–28°C, crowds thin considerably, and prices fall. The light in October is extraordinary.
Winter (November–March): Athens in winter is cool (8–15°C), quiet, and very affordable. Most major sites stay open. Rain is possible but rarely prolonged. A good option for museum-heavy trips and food-focused city breaks without the summer pressure.