· Brisbane sweats through heatwave
· Dust storms, bushfires and heatwaves in January

Thunderstorms are set to roll into southeast Queensland, providing relief from what has been one of the state’s longest heatwaves.

Forecasters say a cool change will see temperatures plunge to as low as 20C.

Bureau of Meteorology senior forecaster Bryan Rolstone says northerly winds will result in the mercury rising to 35C on Monday, but temperatures should then fall.

A late change, including thunderstorms, will sweep through the southeast on Monday evening.

“That will knock down temperatures even further next week to (a maximum) of 27 degrees or so,” Mr Rolstone told AAP.

Mr Rolstone says a second cool change is likely to hit Brisbane next weekend, with thunderstorms and rain to develop in central Queensland during the week.

The change can’t come soon enough for the southeast, where a number of heat records were smashed on Saturday.

Beaudesert, south of Brisbane, reached a top of 44.6C, breaking its previous record of 43.1C set in 1968.

Heat records were also broken at Archerfield, Nambour, Logan, Maroochydore, Redcliffe, Toolara, Beerburrum and Toowoomba.

It was the third day that heat records were smashed in the Sunshine State.

Mr Rolstone says the heatwave is one of the longest Queenslanders have endured.

“This may have been the longest one for a long time, over the interior anyway,” he said.

The heatwave was caused by a build up of hot air in the state’s far north, he said.