Australia has quietly notched a record-setting rise in the mercury, not officially seen before in this century. 

While much of the east coast of the country has been dealing with an unusually wet and cool summer season, it’s been a different story on the insulated west coast. 

On Thursday, multiple locations in Western Australia breached 50°C or higher with a high of 50.7°C recorded in the northwest town of Onslow. 

It’s the first time this century that an Australian weather station has hit the milestone as the Pilbara region endures sweltering heat. 

Onslow reached 50.7°C just before 2.30pm yesterday, according to the Bureau of Meteorology, matching the previous record set in the outback South Australian town of Oodnadatta in 1960.

As meteorologist Ben Domensino pointed out on Twitter, the temperature reading is the equal highest temperature on record in the Southern Hemisphere.

It was one of three stations in the Pilbara region to exceed the 50°C mark, with Mardie and Roebourne Airport both reaching 50.5°C.

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

The scorching heat is expected to somewhat ease in Roebourne and Karratha on Friday, but another 49°C 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 27°C day yesterday. 

According to Weatherzone meteorologist Brett Dutschke, the Pilbara region has been hotter than usual due to warmer than-normal sea surface temperatures off the WA coast. 

“The region is also sunnier than normal given the monsoon (and cyclone) has focussed the cloud/rain on Australia’s northeast,” he said in a blog post, referring to ex-Tropical Cyclone Tiffany.

He also noted the likely impact of continued global warming as a factor in the record temperatures.

The Pilbara’s average January maximum is 40.7°C. 

Before Thursday, Australia had hit the 50°C mark on only a few occasions in the record books. Most recently, the mercury reached 50.5°C at Mardie Station in Western Australia in February 1998. Before that, South Australia’s Oodnadatta saw back-to-back days over 50°C in 1960.

The new norm if we don’t act: Tim Flannery

Speaking to Yahoo News, Australian environmentalist and Chief Climate Councillor Tim Flannery said he wasn’t surprised to see the Australian heat record matched overnight.

“I wasn’t surprised to see Australia’s recored temperature set at Onslow overnight, the records are falling by the thousands – heat, fire, flood, almost anything you look at,” he said. 

“We are moving now out of that historic range of what we’ve experience and survived into a new era. 

“Looking forward a decade that record set in Onslow will look more like the average, if we don’t act, than an extreme event – and that’s deeply concerning.”