The Bureau of Meteorology (BOM) says Queensland's heatwave will extend into next week with temperatures up to eight degrees above the average.
The hottest place in Queensland is expected to be Birdsville in the south west, with the temperature to top 45 degrees today.
In the south east, fire crews are concerned about strong winds and soaring temperatures in their battle to control a bushfire on Bribie Island, north of Brisbane.
About 30 firefighters are continuing to battle a bushfire burning on inaccessible land with more crews and aircraft on standby.
The fire has already burnt out 14 square kilometres of land.
Fergus Adrian from the Queensland Fire and Rescue Service (QFRS) says the fire is not burning close to homes - but it is still a worry.
"With the weather conditions we are concerned," he said.
"We implemented strategies to contain that fire but the weather conditions prevented us from doing that."
New containment lines were established last night around a blaze at Tin Can Bay north of the Sunshine Coast.
The bushfire started on Friday and is burning in an inaccessible area.
No properties are under threat.
Forecast temperatures today include 44 at Winton, 43 at Longreach, 42 at Mt Isa and 41 at Charleville, Rome and Goondiwindi.
High temperatures, low humidity and winds up to 50 kilometres an hour have created severe to extreme fire conditions in the Maranoa, Warrego, Channel Country and parts of the Darling Downs and Granite Belt.
Authorities will send water-bombing aircraft to fight fires on a station near Thargomindah in the state's south west.
The fires started earlier this week and are close to homesteads at the Bulloo Downs property.
A grazier from a neighbouring property Katie Brown says landholders have been helping one another out this week.
She says neighbours spent all of Monday night helping her fight a fire on her property.
"We all need to be able to go as soon as possible - as soon as someone sings out for help we need to have our stuff ready and just go straight away," Ms Brown said.
"As soon as there's a problem they just jump straight in and leave whatever they have to do.
"Nothing's as important as someone's property or infrastructure burning down."
The temperature in Brisbane is forecast to reach 36 degrees today and BOM forecaster Rick Threlfall says a cooler change is not likely anytime soon.
"Normally places like Birdsville will see five or six days in a row of mid forties," Mr Threlfall said.
"This is carrying on beyond that for seven to 10 days and maybe for a few more days yet.
"The hot air has sat over top of western Queensland for at least a week and will make its way eastwards during today."
Mr Threlfall says the heat will continue into early next week and it will be the heatwave's prolonged nature which will make it unusual.
A north easterly wind is pushing smoke from the Bribie Island bushfire towards Brisbane.
© ABC 2013
14:09 EST Severe weather has eased on the New South Wales north coast after two days of heavy rain and flash flooding, but some communities are still cut off.