Australia continues to burn as crews battle bushfires across five states and territories that have threatened homes and scorched hundreds of thousands of bushland.

NSW is under the worst threat with more than 90 fires that have burned more than 350,000 hectares.

Seven of those fires continue to burn out of control.

A 9800-hectare blaze near Cooma threatened 15 homes on Saturday as more than 100 firefighters worked to contain the inferno.

Crews are battling two other major fires near Yass and Sussex Inlet that have threatened homes but eased thanks to cooler weather conditions.

Firefighting crews in Tasmania, Victoria, Queensland and the ACT also fought blazes on Saturday.

Authorities in Tasmania issued a watch and act alert as a bushfire between Forcett and the Tasman Peninsula strengthened.

The Tasmanian Fire Service issued the alert today for communities near the blaze, noting increasing activity on the blaze's boundary in the Kellevie, Bream Creek and Marion Bay areas.

TFS senior station officer Phil Douglas said the fire had expanded to cover 23,600 hectares, and fire crews were backburning to contain the blaze.

Tasmanian emergency services have been fighting fires since January 4.

Several fires were burning across Victoria but they were under control, including a blaze at Kentbruck in the state's south-west, where 66 fire crews remained stationed.

A State Control Centre spokeswoman says the Kentbruck blaze now covers 11,890 hectares, due to backburning as part of containment efforts.

A 13-hectare blaze at Kangaroo Ground on Melbourne's outskirts had been declared safe despite going close to a significant number of properties.

In Queensland, there were 34 bushfires across the state but none threatened homes, while two small grassfires were the only blazes in the ACT on an extreme fire danger day.

AAP