From time to time there is discussion about the inappropriateness of the 'four seasons' model in much of Australia. It's certainly not appropriate in Sydney. Spring started in my garden at least a month ago.
Aboriginal people around the country had different seasonal models (see link below).
Dr Tim Entwistle of Sydney's Botanic Gardens proposes a five season model:
Summer: December, January, February, March
Autumn: April, May
Winter: June, July
Sprinter: August, September
Sprummer: October, November
Read more here.