Late spring (May to June) and early autumn (September to October) are the sweet spot, with warm days, sea still or already good for swimming, and thinner crowds than midsummer. July and August are hot, very busy and pricey, with jammed roads and full beaches, while winter is quiet and mild but with many hotels, restaurants and ferries closed.
The single coastal road is narrow, cliff-edged and busy with buses and scooters, and travel sickness on the bends is common. Sit near the front on the bus if you are prone to it, drive only if confident, and take extra care as a pedestrian where there is no pavement.
The villages are built almost vertically, with countless steps and steep lanes and little that is step-free. Wear sturdy, non-slip shoes, pace yourself in the heat, and be aware that reaching beaches and viewpoints often involves a long climb both ways.
Beaches are mostly pebbly with quick-deepening water and passing boats, so swim within marked areas and mind your footing on wet rocks. Summer sun is strong with little shade on trails and boats, so carry water, sunscreen and a hat, especially on the Path of the Gods.