This week, Victoria recorded its hottest day in nearly six years. On Tuesday, the northwest towns of Walpeup and Hopetoun reached 48.9°C, and the temperature in parts of Melbourne soared over 45°C. Towns in South Australia also broke heat records.

This heatwave is not an outlier. It is a warning shot.

These weather conditions rival the extreme heat seen in the lead-up to the 2019–20 Black Summer, and they point to a future in which days like this are no longer rare, but routine.

What makes this summer so confronting is not just how hot it has been, but this: Australia already knows how to cool cities, yet we are failing to do it. Why?

Cities heat up faster and stay hotter than surrounding areas because of how they are built. Dense development, dark road surfaces, limited shade, and buildings that trap heat and rely heavily on air-conditioning create the “urban heat island” effect.

This means cities absorb vast amounts of heat during the day and release it slowly at night, preventing the city from cooling down even after sunset. During heatwaves, this trapped heat accumulates day after day and pushes temperatures well beyond what people can safely tolerate.

Future urbanisation is expected to amplify projected urban heat, irrespective of background climate conditions. Global climate change is making........

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