Cape Town has a Mediterranean climate — warm, dry summers and cool, wet winters. The best time to visit depends on what you want to do.
Summer (November–March) is the main tourist season. Days are warm (average high around 26°C/79°F), the beaches are in full swing, and the outdoor restaurant terraces on Camps Bay fill every evening. The Cape Doctor, a strong south-easterly wind, blows frequently from December onwards — it keeps temperatures pleasant but can make beach days uncomfortable. In February and early March, the Berg Wind occasionally brings very hot, dry air down off the mountains, pushing temperatures above 35°C.
Autumn (April–May) is arguably the best time to visit: the summer crowds have gone, the weather is still warm and stable, and the wine harvest in the Winelands is underway. The south-easter has dropped and there are long, calm evenings.
Winter (June–August) brings frequent cold fronts from the Atlantic, with heavy rain and strong north-westerly winds. The average minimum drops to around 7°C. Table Mountain is often in cloud. This is low season — prices are lower, the city is quieter, and the mountain fynbos looks spectacular after the rain. August onwards, southern right whales move into False Bay.
Spring (September–October) is flower season: the Namaqualand fields north of Cape Town bloom in August and September, the Kirstenbosch gardens are at their best, and the weather is improving steadily. Whale-watching peaks from August to November, with southern right whales and humpbacks visible from shore at various points along the coast.
The Cape Town Jazz Festival (usually late March) and the Cape Town Carnival (usually March) are the two events most worth timing a visit around.