EMERGENCY alerts are in place as extreme temperatures have caused fires to burn out of control around Australia.

NSW

Dozens of homes under threat as NSW firefighters battle 135 blazes in 40-plus temperatures and "catastrophic" conditions.

The worst fires were in the south, near Cooma, Nowra, Bega and Wagga.

Although 40 fires remained uncontained, by mid-afternoon there had been no reports of loss of life or homes.

Other "emergency" alerts were at Oura, Mates Gully and Munyabla, near Wagga, and Narrandera, southwest of Wagga.

Up to 90 per cent of NSW was in severe danger, with conditions officially described as catastrophic in the Illawarra, Shoalhaven and Southern Ranges.

A total fire ban is in place across NSW.

TAS

A bushfire emergency warning has been issued for Kellevie and Bream Creek in the southeast and Mathinna in the northeast.

The Tasman Peninsula blaze is threatening the small bayside towns of Eaglehawk Neck, Pirates Bay and Doo Town.

Around 40 bushfires continue to burn across the state, with uncontrolled blazes at Montumana in the northwest and Lake Repulse in the Derwent Valley also causing concern.

More than 550 houses have been searched and no bodies found, although about 100 people are still unaccounted for.

VIC

An eight hectare grassfire has burnt the fences of several Sunbury homes in Melbourne's northwest.

The Kentbruck fire in Victoria's southwest continues to burn, threatening the commnuity of Drik Drik, while authorities are on alert for severe fire conditions in the state's north

SA

A string of bushfires continue to burn across northern South Australia but are not causing concern.

The fires, including some which have been burning since Christmas, are in remote areas and are just being left to burn.

QLD

Eight bushfires are burning across Queensland but none are posing a threat to property.

However, fire authorities are on high alert with a week of extremely hot weather about to hit the state.

NT

A bushfire in central Australia forced guests at the Kings Canyon Resort, about 300km southwest of Alice Springs, to evacuate for several hours.

ACT

A forest fire is burning in the ACT's south, close to Mount Ginini in the western region of Namadgi National Park but is under control.

A total fire ban has been declared for Tuesday in the ACT, with fire danger rated at extreme due to forecast very hot and windy weather.

WA

WA has so far avoided bushfires.