Parts of Western Australia’s Pilbara region have sweltered through their hottest day on record with the temperature hitting 50C.

The mercury in Roebourne soared to its new high just before 12.30 pm on Thursday, according to the Bureau of Meteorology.

It puts into the shade the previous record for the town of 49.4C in December 2011.

Karratha, also on WA’s northwest coast, reached 48.4C to exceed its previous high of 48.2C.

WA’s highest temperature on record is 50.5C, posted in February 1998 in the tiny Pilbara outpost of Mardie. The mercury there climbed to 48.4C on Thursday.

The scorching heat is expected to somewhat ease in Roebourne and Karratha on Friday but another 49C day is forecast further down the coast in Onslow.

Temperatures were also well into the 40s in parts of the Goldfields and Gascoyne regions, while Perth enjoyed a mild 26C day.

A severe weather warning has meanwhile been issued for people in parts of the far-north Kimberley region, including Kununurra and Wyndham.

The bureau said a deep tropical low was set to move across the border from the Northern Territory, bringing heavy rainfall and possible flash flooding.

Damaging wind gusts up to 100km/h are anticipated from Thursday afternoon.

– AAP