However, the warning from Dampier to Whim Creek, including Roebourne, Pt Samson and Karratha, has been cancelled.
Port Hedland Mayor Kelly Howlett said that although the intensity of the wind was lessening, there was lots of rain.
"There are about 2000 houses without power at the moment and lots of trees have fallen down."
She said the cyclone was not as disastrous as Cyclone George in 2007, which was a category 5 and killed three people.
The Department for Child Protection has set up a relocation point in South Hedland.
The weather bureau said gales with gusts of up to 120km/h were still occurring in some areas.
Heavy rainfall up to 250mm was likely across the central and eastern Pilbara.
Tides along the Pilbara coast would be higher than normal although the threat of a dangerous storm tide had now passed, the bureau said.
A flood warning had been issued for the Pilbara coastal streams between Port Hedland and Karratha. Emergency services advised people in the area to prepare early to relocate equipment and livestock.
Port Hedland's airport and bulk export port remained closed.
Mining firms across the region have sent home all non-essential workers.
Tropical Cyclone Heidi is the second cyclone of the season for the WA region and the first to affect the mainland.
- AAP