Karratha has copped a downpour of 210 millimetres in the 24 hours to Thursday morning, making it its wettest February day on record.

As roads turned to rivers in the Pilbara town, there was one man who stood out in the flood waters and directed traffic, his half-submerged body allowing drivers to see how deep the waters were.

Social media lit up overnight with dozens of photos and videos of people navigating the wild weather, with resident Paula Maher capturing waters gushing through an underpass.

"Just a bit wet here at camp," wrote one fly-in, fly-out worker.