Hottest day on record in parts of Western Australia as temperature reaches 50C

The mercury in Roebourne soared to its new high just before 12.30pm 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.

That reading has only ever been exceeded once in Australia, with a 50.7 degree day set at Oodnadatta in the South Australian outback on 2 January 1960, according to bureau data.

La Nina years are characterised by the tropical Pacific Ocean absorbing more heat than in a neutral year.

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.