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Heatwaves in Melbourne, and the night of the cool change

Melbourne heat often arrives on a northerly and breaks with a cool change. Many nights still drop. Open when outdoor air is cooler than the room.

Melbourne’s heat comes in bursts. A hot northerly can push the afternoon very high, then a cool change from the south arrives and the night falls. On the Bureau of Meteorology’s long-term city table, the November minimum is about 10.4 °C and the January minimum about 13.6 °C. Most nights in this city still do the job a European heatwave night cannot. The difficult night is the one before the change, and the apartment that stored the day.

The bay and the south-east feel the change first. Northern and western suburbs, and dense inner streets, hold heat longer. That lag is an urban heat island, smaller than the drama of the change itself, but enough that a CBD flat and a bayside room are not the same evening.

Use the change, do not get ahead of it

  • While the northerly is hotter than the room, keep the glass shaded and the windows shut. See protect your windows
  • When shaded outdoor air drops below indoor air, that is the night flush. It can be short if you waited all day
  • Brick terraces and top floors release heat slowly. A cool outdoor reading does not empty the room in ten minutes. See top-floor heat
  • A fan on people covers the gap while the building catches up. See where to place a fan
  • Smoke from bushfires some summers is dirty air versus indoor heat
  • Pollen maps in Ventilate cover Europe (CAMS). An empty row in Melbourne does not close the windows
  • Compare indoor and outdoor air before you turn on the air conditioning

Practical Melbourne night

  • Do not treat a mild November night as a failed flush. The long-term minimum is still near 10 °C
  • On a heatwave evening, wait for outdoor air to be cooler than the room, then open
  • Prefer the cooler side of the building as intake if you have two façades
  • If the change has not arrived and both temperatures sit in the high 20s, close and cool people first

Tonight follows your indoor thermometer, not the city’s reputation for cold.

Shade and less bare paving still decide how long a street keeps the afternoon: heatwaves and public choices.

Updated

Sources and further reading

Official guidance supporting the practical advice on this page.

Links checked 29 August 2026.

More in this guide

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Heatwaves in cities, and why nights stay hot · All guides

These guides are informational and are not medical advice. If heat is making you unwell, follow your local health agency’s guidance.