Extreme fire warnings have been issued for parts of Queensland as 28 blazes burn across the state and firefighters prepare for big winds to sweep through tinder dry areas.

The fire danger will peak in the Darling Downs and Granite Belt on Friday afternoon with temperatures across the southeast expected to soar toward 40C.

Forecasters say extreme warnings are in place from the Gold Coast to the Sunshine Coast, inland to Toowoomba and then out towards Dalby, Miles and Goondiwindi.