One of the great things about living in Sydney with such an entirely agreeable climate is the lack of clearly defined seasons. Winter turns into Spring, turns into Summer etc usually without clearly defined moments. Unlike those who live in colder climates, we just don’t have events like “the first snow of winter”.
Today, however probably marks the first day of winter with Sydney enveloped in a fairly thick fog. There are international diversions at the airport, and the Manly Ferry has been replaced by buses. So yeah, I guess today marks the first “official” day of winter in Sydney.