Sydney airport hottest place in NSW as parts of the city hit 40C

Parts of Sydney became the hottest places in New South Wales as the temperature soared to 40C on the Australia Day public holiday.

Intense heat descended across Sydney on Tuesday, with the city centre reaching 37C at midday, above a forecast of 36C.

Penrith and Badgerys Creek in the city’s west reached 40C, while the Bureau of Meteorology’s observation station at Sydney airport reached 40.3C.

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“The hottest place in the state right now is Sydney airport,” Bureau of Meteorology duty forecaster Dean Narromore said. “The hottest areas in the country are focused on the Sydney area.”

Parts of western Queensland and northern NSW also reached 40C. A cool change is expected in Sydney by Tuesday night, with the NSW fire risk remaining low.

Conditions have eased in other parts of the country, even as the bureau issued a warning that a cyclone was “likely” to form in northern Australia over the next few days.

From Tuesday onwards, the likelihood of a tropical low in the Gulf of Carpentaria intensifying into a cyclone will increase from less than 5% to over 50% by Thursday.

“Conditions are favourable for it to intensify and we are expecting it to remain over water over the next couple of days at least, so it’s likely to become a tropical cyclone by Thursday,” meteorologist Pieter Claassen said.

A tropical cyclone watch has been declared between Aurukun and Karumba, as well as on Mornington Island, in Queensland’s far north.

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If it does develop, it will be the second cyclone this year for the region after Tropical Cyclone Imogen crossed the coast near Karumba on 3 January.

Gales with gusts of up to 110km/h may develop around coastal and island communities late on Wednesday and into Thursday. The developing system coincides with very high tides.

“If the system does form, it is likely that we’ll see abnormally high tides, with tides exceeding the highest astronomical tide,” Claassen said on Monday.

Narromore told Guardian Australia on Tuesday that Queensland’s far north could still expect temperatures of up to 40C.