TOURISTS holidaying in far north Queensland had little time to react overnight as flash flooding tore through two of Cairns' biggest caravan parks.

It was a terrifying, sleepless night for 42 holiday-makers who were almost swept away by heavy rain brought on by ex-tropical cyclone Nora.

More than 600mm of rain fell in some areas, with one tourist telling Today he woke up to his caravan park full of water.

"Within 10 minutes it grew up to one metre. Lots of motor homes just swept away," he said.

Speaking to the Today show, SES far north controller Sean McGuinness said a number of people called triple-0 in relation to flash flooding at Redlynch Valley.

SES rescue crews responded to calls from two different caravan parks, including the BIG4 Cairns Crystal Cascades park.

"There was access issues to those people. Swift water people were sent in first and flood boat crews were tasked to assist for that situation, just because of the number of people that were reported. 42 people were evacuated by swift water rescue crews," Mr McGuinness said.

"The water did go down quite quickly and the swift water equipment was used to do that. SES crews arrived to do a response to deal with those people that had been evacuated," he added.

Flash flooding hit Cairns overnight.
Flash flooding hit Cairns overnight.

While no-one was injured from the flash flooding, Mr McGuiness said the speed at which the caravan parks were inundated meant there was a lot of damage they had to assess.

"Some people did have the opportunity to get their belongings and others said their belongings were still in the caravans. There was one report that a rental car had been swept away from where a person had parked it the night before. There was a lot of damage and light will tell us how bad the damage is," he said.

A number of caravans and cabins were inundated.
A number of caravans and cabins were inundated.

The SES will remain on standby this morning with more rain expected to fall. Up to 200mm is predicted over far-north Queensland as ex-tropical cyclone Nora makes it way off Australia.

Emergency crews are particularly worried about this morning's high tide.

Cairns council has warned residents that major flood levels are occurring on the Barron River at Caravonica, Kamerunga and Lake Placid.

Queensland Fire and Emergency Services Commissioner Katarina Carroll told the Cairns Postthere was still a risk of flash flooding from Cape Tribulation in far north Queensland to Townsville.

"Tropical Cyclone Nora has been downgraded but there is still increased rainfall for coastal areas of the far north as the system moves west," Ms Carroll said.

"The current heavy falls we are seeing are in addition to recent downpours that saw flooding in Ingham and Innisfail, and flood warnings are still in place for many rivers."