An extreme fire danger warning has been issued for parts of Queensland due to soaring temperatures across the state, as multiple fires continue to burn.
There are also warnings of extreme fire danger in NSW and a warning for catastrophic fire conditions in the Northern Territory.
The Bureau of Meteorology has issued warnings for the Darling Downs and Granite Belt west of Brisbane with temperatures set to reach 35C.
"These conditions are really being driven by quite hot, gusty northwesterly winds and very dry conditions," Senior Meteorologist Kimba Wong said.
"With underlying dry fuel that's in the landscape that's resulting in those high fire danger ratings and will make fire suppression really challenging for our firefighters today."
Forecasters expect temperatures to drop to October averages in the coming days.
Authorities on Monday were managing 18 vegetation fires across the state with more than 60 burning in the past 24 hours, Queensland Fire and Emergency Service said.
The biggest concern on Monday afternoon was a grass fire west of Brisbane with about 20 crews including water bomber aircraft working to bring it under control.
The QFES issued a "leave immediately" emergency warning late on Monday for residents in the Wutul and East Cooyar region near Toowoomba.
The QFES warned properties in the area that it may soon be too dangerous to drive with a fast-moving fire burning Dukes Road and expected to impact East Cooyar Road.
The BoM issued fire weather warnings for parts of NSW, including the Far North Coast, Greater Hunter, Greater Sydney Region, New England, Northern Slopes and North Western districts due to high winds.
Total fire bans are in place.
The NSW RFS carried out a series of hazard reduction burns ahead of Monday's extreme fire conditions, with the burns suspended while the weather warnings and strong winds remain in place.
The bureau's Miriam Bradbury said gale force warnings were in place for the NSW coastline from the Byron Coast down to Eden.
"Many parts of Australia are seeing high fire danger ratings, with a number of districts sitting in extreme," she said.
"These extend from the mid-west coast of WA, all the way to northeast NSW, and the Darling Downs and Granite Belt in Queensland."
Damaging winds of up to 70km/h with peak gusts about 100km/h are expected in central NSW and from Wollongong to Forster, before easing later on Monday evening.
There are warnings in place for catastrophic fire conditions in the Barkly North district in the NT, with several fires burning and roads closed.
"In such dangerous conditions, it is imperative that you seek advice from your local fire and emergency services, and keep yourself up to date with the weather conditions," Ms Bradbury said.
Extreme conditions will remain in place for the NT and Queensland for Tuesday, but northeastern NSW can expect a cold front late on Monday.
The cool change will shift north throughout the week, but the heat will persist inland in Queensland and in the NT.
