Late spring (May, June) and early autumn (September) are the best months. The weather is usually warm but rarely hot, the seafront is busy without being packed, and the long evening light lasts late.
July and August are the busiest months. The seafront fills up, the hovercraft and ferries run hot, and the Victorious Festival takes over Southsea Common in late August — three days of music with around 70,000 visitors each day. The Great South Run, a 10-mile road race, is held every October and draws around 25,000 runners.
Winter (November to February) is mild but often wet and grey. Many of the seafront attractions wind down to weekend openings. The dockyard is open year-round but quieter — a real advantage if you want HMS Victory more or less to yourself.