Parts of southern Queensland received their best rain in six decades during the last 24 hours.

A slow-moving low pressure trough interacting with an upper-level low pressure system caused heavy rain and storms in the state's southern and central inland on Tuesday and Wednesday.

Some areas in the Maranoa and Warrego District picked up 100-150mm of rain during the 24 hours to 9am on Wednesday. Mungallala's 149mm was their heaviest daily rainfall in 60 years.

Nearby, Mitchell's 51mm was their heaviest rain in two years and nearly doubled their monthly average for this time of year.

Whie the downpours caused localised flash flooding, it was welcome rain for Queensland's parched southern inland. Mitchell received less than 30mm of rain during the first three months of 2019, which is well below their long-term average of 214mm between January and March.

Roma's 44mm during the 24 hours to 9am on Wednesday was their heaviest rain in 14 months. This will help freshen up the town's flora before the Roma Show, which takes place in a couple of weeks.