South-east Queensland is about to get unusually hot again, with Brisbane expecting temperatures 8 degrees Celsius above average next week.

The warmer weather is set to arrive tomorrow and will be a sharp turnaround from this morning, which was the coldest of the month so far, falling to 3C at Archerfield, -1C at Gatton and -0.4C at Amberley.

"It's funny, sometimes you get the cold mornings with the hot days just because the skies are clear, which allows the air to cool down a lot overnight," Bureau of Meteorology forecaster James Thompson said.

But mornings will be warmer as the unusually hot weather settles in, coming on the back of Queensland's hottest July on record.

"We're going to have warm conditions for the next week, getting up towards 30C at times," Mr Thompson said.

"Temperatures will creep up over the week with a ridge of high pressure over us, and then we have an approaching trough next week really which brings in that hot air from the centre of the state."

The peak in the winter heatwave is expected by Wednesday, just in time for the Brisbane Ekka public holiday.

"It's going to be a beautiful Ekka, I reckon."

Toowoomba and the Sunshine Coast are predicted to hit 29C next Wednesday, with the Gold Coast expected to hit 28C.

Bracing for 'lengthy bushfire season'

The hot July and precious little rain has also set the stage for a worrying fire season across Queensland, authorities have said.

Rural Fire Service operations director Chief Superintendent Gary McCormack said authorities were now looking at an "average to above-average fire season", with areas of open grassland most at risk.

"We certainly have experienced continual above-average temperatures and below-average rainfall and that's all contributing to what is potentially another busy fire season," he said.

Rain brought on by Cyclone Debbie has increased bushfire fuel loads across Queensland. ( AAP: John Casey - file photo )

"We're certainly prepared for all outcomes."

He said the rain brought by Cyclone Debbie in late March had increased fuel loads through the eastern interior right down to the border.

The destocking of outback properties over three years of drought had also contributed to the increased fire risk.

"Open grassland areas that've been exposed to the drying conditions of winter, that's where we'll see the start of the fire season more predominantly," Superintendent McCormack said.

"We're certainly looking at the Burnett area, and western areas out through Mount Isa, Cloncurry and Biloela — they've all experienced some increased fuel loads and they've certainly got potential as well."

Lengthy fire season expected

He said local brigades and fire service staff would be engaging with their communities to prepare for what could be a lengthy fire season.

"It will continue right throughout spring and it could continue post-Christmas," he said.

"This year we had fires right up until February, which was really unusual for Queensland, because normally we're well into storm season by then and we're starting to see some really high humidity and some decent rainfall."

Queensland residents could help by being responsible with their use of fire, and alerting local authorities to risks and hazards.

"They should be getting their house ready for the season by clearing out gutters, and just keeping their yards clean and getting a plan in place," he said.

"For people on the land they're usually very well prepared and they'll be putting their fire breaks in place and making sure that they're ready."