Australia Weather News

A once-in-100-year rain event has pummelled Townsville in north Queensland, causing flash flooding that caught some motorists off-guard.

The Aplin Weir, south of the CBD, received 91 millimetres in 30 minutes as a coastal trough combined with a band of severe thunderstorms about 7:30pm on Monday.

That rainfall climbed to more than 143mm in an hour and 181mm in two hours.

Nearby Annandale had 62mm in half an hour and Kirwan had 56mm.

Bureau of Meteorology (BoM) forecaster Michelle Berry said it was history-making rain.

"It is exceptional and quite extraordinary," Ms Berry said.

"It was a one-in-100-year event. Very, very intense rainfall ... and we had some pretty significant flash flooding concerns up through there."

Firefighters were called to help two motorists after several roads were submerged, but both made it out safely before crews arrived.

Ms Berry could not say if the rain was record-breaking as the heaviest falls were not where BoM held records.

Rain misses dam

The rain was not enough to prevent tighter water restrictions.

Mark Harvey from Townsville City Council said dam levels had only increased by half a metre.

"The rain pretty much fell everywhere except the Ross Dam catchment unfortunately," he said.

"We received on average about 30 millimetres across the catchment."

The coastal trough has moved north and storms are forecast for Ingham, and the system would then head towards Cairns.

Cairns duty forecaster Bill O'Connor said the rain had brought some relief from the stifling conditions.

"From early to mid-afternoon we'll start seeing some showers back onto our coast and probably a little bit of an increase in the shower activity for the Cairns region overnight tonight and into tomorrow," he said.