On Tuesday, a woman and child were rescued after their car flipped on its side in fast-flowing waters near the Warrego Highway near Charleville.
The Bureau of Meteorology is warning people in the state's southwest and coastal communities from the Gold Coast north to Hervey Bay to be prepared for flash flooding and damaging winds.
Two low pressure systems are responsible for the rain, which has set new records in some communities.
Other inland communities have been left isolated by the rain. They include Birdsville and Bedourie.
Charleville received 145mm in the 24 hours to 9am on Tuesday, while other parts of southwest Queensland, including Mitchell and Quilpie, received up to 165mm.
Parts of Brisbane received more than 100mm of rain, with flash-flooding closing a number of roads and heavy winds bringing down trees.