Athens has one of Europe's finest climates. Summers (June–August) are hot and dry at 32–36°C — sightseeing before noon and after 5pm is advisable. The Athens heat is dry, making it more bearable than humid alternatives. Winters (December–February) are mild at 9–13°C with some rain — very comfortable for walking and sightseeing without crowds.
Spring (April–May) is arguably the best time: wildflowers bloom on the Acropolis hill, temperatures are perfect at 18–24°C, and crowds are manageable. Autumn (September–October) is similarly excellent. July–August peak season brings maximum tourists and heat. Easter week in Greece is spectacular — the candlelit midnight service at churches across the city is unforgettable.