A strong wind warning is also current for Western Port, Gippsland Lakes and West Coast.
The conditions come after a freezing cold day yesterday as snow fell across the peaks in both states.
Temperatures hovered around 20C at lunchtime in Sydney however it felt more like 12C.
At 12:30pm yesterday:
Canberra was 9.8C with an apparent temp (feels like) of 2.9C
Sydney was 19.5C with an apparent temp (feels like) of 12.9C
Thredo Top Station, elevation 1957m, was -2.8C with an apparent temp (feels like) of -17.8C
Ski resorts reported falls of 5 to 10 centimetres overnight with more falling constantly throughout today.