A trough and front crossing South Australia is triggering gusty showers, with the odd shower extending to western Victoria, southwest New South Wales and Tasmania.
A Tasman Low meanwhile is generating huge waves along the NSW coast, with a hazardous surf warning issued.
A trough over southwest West Australia will cause more showers and storms, but other regions are set for clear weather, under the influence of a high.
A marine wind warning has been issued for WA, SA, NSW, Victoria and Tasmania.
Here's the weather forecast for Sunday:
Light winds will become NW 15 to 25 km/h in the morning. Temperatures will range from 8 to 20C.
A severe weather warning is in place for residents in parts of the Illawarra, South Coast, Southern Tablelands and Snowy Mountains forecast districts.
Melbournians are in for partly cloudy skies, with a high chance of showers, most likely in the late afternoon and evening, increasing to a very high chance across the eastern suburbs.
There remains a chance of a thunderstorm in the evening and possible hail in the evening.
Winds N 25 to 40 km/h turning NW 25 to 35 km/h are forecast in the late afternoon.
The mercury will dip to a low of 8 degrees Celsius before climbing to a high of 15.
A severe weather warning is in place for residents in parts of the East Gippsland, South West, North East and West and South Gippsland forecast districts.
Sunny weather is ahead today, with light winds. Brisbane residents will enjoy a temperate high of 24C, up from a low of 11C.
The thermometer will fall as low as 7C and reach a high of 17C.
Winds NW 25 to 35 km/h will turn W/SW 30 to 45 km/h in the morning.
A low of 10C and a high of 15C is expected.
Snowfall above 800 metres has been forecast in the evening.
Winds N/NW 25 to 35 km/h will decrease to 15 to 25 km/h early in the morning then tend W/NW 20 to 30 km/h in the evening.
Temperatures will range between 6C and 13C.
Temperatures have plunged to 2C and will reach an eventual high of 14C.
Light winds will become NW 20 to 30 km/h in the morning.
A steamy high of 31C has been forecast, following a low of 19C.
A Tasman Low meanwhile is generating huge waves along the NSW coast, with a hazardous surf warning issued.
A trough over southwest West Australia will cause more showers and storms, but other regions are set for clear weather, under the influence of a high.
A marine wind warning has been issued for WA, SA, NSW, Victoria and Tasmania.
Here's the weather forecast for Sunday:
New South Wales
Mostly sunny weather is expected in Sydney, with areas of fog in the early morning, mainly in the west, and patches of light morning frost in the outer west.Light winds will become NW 15 to 25 km/h in the morning. Temperatures will range from 8 to 20C.
A severe weather warning is in place for residents in parts of the Illawarra, South Coast, Southern Tablelands and Snowy Mountains forecast districts.
Victoria
There remains a chance of a thunderstorm in the evening and possible hail in the evening.
Winds N 25 to 40 km/h turning NW 25 to 35 km/h are forecast in the late afternoon.
The mercury will dip to a low of 8 degrees Celsius before climbing to a high of 15.
A severe weather warning is in place for residents in parts of the East Gippsland, South West, North East and West and South Gippsland forecast districts.
Queensland
Sunny weather is ahead today, with light winds. Brisbane residents will enjoy a temperate high of 24C, up from a low of 11C.
Western Australia
It will be mostly sunny over Perth, with light winds becoming E/NE 15 to 20 km/h in the morning then lighter in the middle of the day.The thermometer will fall as low as 7C and reach a high of 17C.
South Australia
Partly cloudy conditions are forecast for Adelaide, with a high chance of showers, easing during the late morning and mostly clearing by midafternoon.Winds NW 25 to 35 km/h will turn W/SW 30 to 45 km/h in the morning.
A low of 10C and a high of 15C is expected.
Tasmania
Partly cloudy weather in Hobart also, with a high chance of showers, most likely in the late afternoon and evening.Snowfall above 800 metres has been forecast in the evening.
Winds N/NW 25 to 35 km/h will decrease to 15 to 25 km/h early in the morning then tend W/NW 20 to 30 km/h in the evening.
Temperatures will range between 6C and 13C.
Australian Capital Territory
Today will be partly cloudy in Canberra, in addition to light winds, becoming NW 20 to 30 km/h in the morning.Temperatures have plunged to 2C and will reach an eventual high of 14C.
Light winds will become NW 20 to 30 km/h in the morning.
Northern Territory
There is a chance of fog in the early morning in Darwin, but an otherwise sunny day is expected, with some light winds.A steamy high of 31C has been forecast, following a low of 19C.