Spring (April to June) and early autumn (September and October) are the sweet spots, with warm, sunny days, manageable crowds and perfect weather for day trips to Pompeii and the coast. July and August are hot, humid and very busy, with many locals away in mid-August, while winter is mild but wetter and some sights keep shorter hours.
Naples has a real reputation for pickpocketing and bag-snatching in crowded areas, on public transport and around the main station. Keep valuables secured and out of sight, use a zipped cross-body bag, and avoid displaying expensive phones or jewellery in busy streets and markets.
Traffic in Naples is famously chaotic, with scooters weaving through gaps and crossings treated as suggestions. Cross with locals, make your movement predictable, and stay alert on narrow pavements where mopeds sometimes ride. Take particular care with children in the old town's lanes.
Naples is generally safe for visitors by day, but some outer and inner neighbourhoods feel edgier after dark. Stick to busy, well-lit streets at night, keep to the main tourist and seafront areas, and take a taxi rather than walking through quiet districts late.