Queensland's Bureau of Meteorology (BOM) has warned conditions will intensify over the coming days, and worsen this weekend.
Humidity temperatures could cause storms to emerge, as the tropical season hits the state's main cities.
"Parts of the south-east may also see severe storms, with potential heavy rain or damaging winds, plus a slight risk of large hail," the bureau warned.
Afternoon rainfall is expected to follow in isolated thunderstorms, mostly inland.
Areas affected by the heatwave include Bundaberg, Gladstone, Gympie, Gold Coast, Ipswich, Mackay, Maroochydore, Maryborough, Yeppoon and the Brisbane metropolitan area.
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