Perth and large parts of Western Australia are expected to swelter through yet another scorching summer, with the chance of record-breaking heat likely, according to the Bureau of Meteorology.
The long-range outlook for the season, released today, has projected both day and night time temperatures to be hotter than normal for the majority of the state.
The Bureau's WA Manager James Ashley said the outlook showed a very similar scenario to the summer of 2021/22, which was Perth's hottest ever and delivered a record number of days in excess of 40 degrees Celsius.
With the southern half of WA primed for harsh, dry summers in a normal year, Mr Ashley said it meant an increased risk of heatwave conditions.
"We find that when we do have these hotter than normal summers we tend to break records," he said.
"We tend to have either really hot days, or periods of hot temperatures leading to those heatwave conditions like we had last summer.
"And as far as the signal for this summer, it really is a high chance of having those heatwave conditions or those extremely hot days."
Much of the Northern Territory and Tasmania have also been projected to have hotter-than-normal temperatures from December to February.
The only exception in Western Australia was the south-coastal regions, east of Denmark, which have been tipped for average to slightly below average temperatures.
Cool November no indication of what's to come
The summer outlook marks a stark difference from what Perth residents have experienced during spring.
Perth is currently on track to record one of its coolest November on record, in terms of maximum temperatures.
The Bureau's outlook has also projected mild to cooler-than-average temperatures during December for most of the southern half of the state.
But Mr Ashley said despite the gentle lead-up, it was unlikely to be a gradual transition into the hot weather.
"Typically, it just changes," he said.
"We had a really hot day on Tuesday, and we're looking at getting into the high 30s next week.
"While we're not saying the cool days are definitely gone, the hot days are becoming more likely as we head toward summer."
A 'tale of two outlooks'
While WA bakes, the eastern half of the country has been tipped for vastly different conditions this summer.
"The outlook is really a tale of two things," he said.
"There is a really strong hot signal for the west, and a wet signal for the east."
He said given the already sodden landscape through parts of the south-east of Australia, any amount of rainfall presented a flooding risk.
"Not much rain at all will still produce flooding response because the rivers are so swollen and the ground is so wet," he said.
Lack of sea breeze drives heat
Mr Ashley said the main driver behind the hot summer outlook for WA was the predicted strength of hot desert winds which fan over the southern half of the state.
He said this was driven by the position of high-pressure systems, and the west coast trough – a signature feature during the summer months in WA.
"So if we have those high-pressure systems sitting in the Great Australian Bight, typically it pushes the really hot winds from the north-east across the south of WA and the trough stays offshore for longer," he said.
"It's basically just pumping hot, dry north-easterly winds across the southern half of the state and the sea breeze is struggling to penetrate against those north-easterly winds."
The summer outlook for Western Australia is consistent with the long-term climate trends for the state, and across the country.
According to the to latest State of the Climate report, released on Wednesday, warming has been observed across Australia in all months with both day and night-time temperatures increasing.
The report said the change had been accompanied by an increased number of extreme heat events, including a greater frequency of very hot days in summer.
