Australia Weather News

Perth is experiencing its first heatwave of the summer, as the city surpassed 40 degrees Celsius for the first time since February.

A low to severe intensity heatwave has been dominating large parts of the state's central and southern regions since Sunday, slowly expanding further south.

Perth hit a top of 40.4C on Wednesday afternoon, making it the hottest day since last summer, with the temperature only dropping to 21.8C overnight,about 5C above the December average minimum.

That was almost the same as Tuesday night, when a similarly warm low of 21.7C was recorded.

The hottest temperatures in WA on Wednesday were from south of Geraldton to the Central West, Central Wheatbelt and the northern and eastern parts of Perth.

Gingin Airport recorded the state's highest maximum with 43.1C just before 2pm.

Pearce airstrip clocked 43C, the Swan Valley reached 42C and Perth Airport 41.9C.

It's still a few degrees off the December record, which was recorded at 44.2C on Boxing Day in 2007.

A static pattern with a deep west coast trough has been the culprit for the sweltering conditions, drawing hot north-easterly winds from central WA to the South West.

However, the trough is expected to move inland on Thursday helping cool down coastal areas over the coming days.

Temperatures in Perth are set to reach a maximum of 35C on Thursday, with a cooler 31C on Friday.

Weekend cooler

A more pleasant change will start from the weekend, with a top of 28C for Saturday and 24C on Sunday, with cooler overnight minimums below 20C.

The Bureau of Meteorology's Angeline Prasad warned the heat was a sign of things to come this summer.

"A combination of the daytime and overnight temperatures are causing severe heat wave conditions at the moment and these conditions are expected to last for the next few days," she said.

"Our hottest month is February, so we'll continue to see warmer temperatures.

"January and February are looking warmer than average for the entire state."

The bureau is also warning those most at risk during a heatwave include children, pregnant women and the elderly, urging them to stay hydrated and remain indoors as much as possible to prevent hospitalisation from heat stress.

Ms Prasad said Christmas will also likely be on the warmer side this year, with the official outlook set to be released on 18 December.

It's a stark contrast to conditions in WA's north, where showers and thunderstorms have kept maximum temperatures cooler, in the mid to high 30s.

Those conditions have been mainly driven by a tropical low off the Pilbara coast, which previously had a low to moderate chance of turning into a cyclone, but is now expected to weaken and move away from the coast.

It comes after 2023's unprecedented spring heatwave in Perth and the south-west brought an unusual run of scorching temperatures to make it the hottest November on record.