A cyclone warning that forced the evacuation of Port Hedland and Dampier ports has been downgraded.
On Monday, a tropical low offshore from the west Kimberley coast was expected to turn into a cyclone.
The port of Port Hedland commenced port and anchorage evacuations yesterday and closed.
The port of Dampier was also shut down as a precaution.
The Bureau of Meteorology said the cyclone warning had now been cancelled.
"It's a very weak system," BoM forecaster Adam Conroy said.
Pilbara Ports Authority reopened the ports of Port Hedland and Dampier at 5am (AWST) this morning.
The port of Port Hedland was officially closed for 10 hours.
The port of Dampier was officially closed for 17 hours.
Cyclones are common in WA’s MidWest region and can cause disruptions to the production and shipping of iron ore.