Iron ore miners Fortescue Metals Group, Atlas Iron and BHP Billiton have evacuated staff and locked down operations in the Pilbara as wind gusts strengthen to 230km/h near the centre of Cyclone Rusty.
Rusty has been upgraded to a category four - the second highest on a strength scale of five.
A cyclone warning has been issued for the Pilbara coast including Port Hedland, the nation's largest bulk commodities port, where port and rail activities have been suspended.
BHP said it was continuing with extreme weather preparations across its mining operations in anticipation of the cyclone moving further inland.
"Additional operations will be suspended if necessary," the company said in a statement.
"Our highest priority is to ensure the safety of people."
BHP said any material effect on production would be detailed in its next quarterly production report.
Rio Tinto mine operations have so far been unaffected by the cyclone but rail and port closures are expected to have an impact on shipments.
Fortescue said its community, training and accommodation sites in Port Hedland had been shut and all port and rail operations in Port Hedland had been locked down.
"All of our people have returned home or to accommodation sites and have been advised to stay indoors," Fortescue said.
"All other Fortescue sites continue to prepare for the cyclone and will update plans accordingly."
The company said it taken precautions to protect its people and all work had been suspended on site.
When Cyclone George ripped through the Pilbara in 2007, the category five storm killed two people at a Fortescue rail construction camp and injured others who were sheltering in work dongas.
An Atlas Iron spokesman said all employees from the company's mine site 100km south of the town of Pardoo had been evacuated.
"We're expecting it to really hit around late this afternoon or early evening," the spokesman said.
"It's just wait and see at the moment."
The Bureau of Meteorology predicts the cyclone will move south on Wednesday.
Port Hedland has already had wind gusts up 120km/h, with conditions set to worsen throughout the day and destructive wind gusts of more than 165km/h are predicted in the area as the cyclone approaches the coast.
Rusty's massive size and slow movement is set to unleash torrential rain and cause major flooding in the De Grey catchment and significant flooding in the Fortescue catchment and Pilbara coastal streams.Rising tides could also cause storm surges and flooding.
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