The last time Sydney recorded a day of 32 degrees or higher was December 19, 2021.

The heatwave is expected to send temperatures soaring in the western suburbs with a maximum of 39 degrees forecast for Penrith on Saturday.

The Bureau of Meteorology’s Helen Reid explained the heatwave was the result of a build-up of hot air in the atmosphere across Australia, which was affecting temperatures nationwide.

“It just really happens when there isn’t a significant change in the set-up we have at the moment,” she said.

“We’ve got a persistent active phase of the monsoon over northern Queensland and into the Northern Territory as well and across the south we haven’t really had much in the way of any cold fronts.”

The record heat is set to hit north-western Australia the hardest with temperatures predicted to reach up to 50 degrees in some parts of the west Pilbara district in Western Australia.

“There’s little weak troughs moving through, but they’re not actually breaking up the atmosphere as much,” she said.

“It’s allowing that heat just to keep filtering in from the north and just to keep building and not get refreshed.”

The NSW Rural Fire Service has already issued an alert ahead of the heatwave, warning the event could result in bushfires.

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“Increased temperatures will bring elevated fire risk to many parts of the state, with some areas likely to experience high and extreme fire danger,” a statement from the RFS said.

The bureau has warned anyone who may be affected by the heatwave to remain somewhere cool over the coming days.

“Close your windows and draw blinds, curtains or awnings early in the day to keep the heat out of your home,” it said in a statement.

“If available, use fans or air-conditioners to keep cool.”

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