Winters are cool rather than cold.
The huge Festival of Sydney takes up most of January. It's the umbrella for a number of events from open-air concerts in the Domain, to street theatre and fireworks. The Great Ferry Boat Race and the more serious Sydney to Hobart Yacht Race are also in January. The more traditional 12-day Royal Easter Show brings the country to the city. The Sydney Film Festival takes place in June, and the 14km City to Surf Run in August.