The ideal months are May, June, and September. The weather is warm enough for swimming and hiking without the crush of July and August, when Camogli fills with Italian holidaymakers and the narrow streets become genuinely crowded. Accommodation prices drop sharply after the first week of September and the light on the painted facades is arguably better in the lower sun of early autumn.
The second weekend of May brings the Sagra del Pesce, Camogli's annual fish festival. On Saturday night the harbour is lit with bonfires and fireworks; on Sunday the town produces what it claims is the world's largest frying pan — around four metres in diameter — and fries thousands of fish from the local cooperative to distribute free to the crowd. It is rowdy, generous, and worth timing a visit around.
Winter is mild by northern European standards, with temperatures rarely dropping below 5°C. The town is quiet, many restaurants keep reduced hours, and the boat service to San Fruttuoso runs less frequently or not at all. The hiking trails on Monte di Portofino are beautiful and uncrowded, and you can have the harbour to yourself in the mornings.