The Victorian town of Walpeup reached 47.1 degrees Celsius during a widespread Australian heatwave, the state's hottest reading since the beginning of the destructive 2019–20 Black Summer fire season.
Temperatures across large areas ran 12 to 16 degrees above seasonal averages. Coastal districts generally faced highs from the upper 30s into the low 40s, while inland locations were expected to move further into the 40s. The Bureau of Meteorology classifies a heatwave through three consecutive days when both daytime peaks and overnight minimums are unusually high for the location and time of year.
Victoria experienced some of the most severe conditions. Melbourne was forecast to exceed 41C, its hottest day of 2024 and hottest December day since 2019. Much of the state was under a total fire ban, excluding East Gippsland and north-eastern Victoria. Fire authorities warned that heat, wind and dry thunderstorms could produce a difficult environment for crews even where recent rain had reduced immediate fuel dryness.
The heat was national in scope but uneven in timing. Parts of western Queensland were forecast to reach the mid-40s, with very warm nights across the Gulf Country and inland districts. Severe or extreme heatwave conditions also affected large parts of the Northern Territory, including the Top End and several interior districts.
New South Wales faced a hotter outlook the following day. Sydney's central district was expected to reach 33C, while Penrith and Richmond could hit 42C and several other western suburbs were forecast near 40C. Authorities monitored lightning activity because repeated hot days could quickly dry grass and increase ignition risk.
South Australia combined high temperatures with strong-wind warnings and the prospect of dry thunderstorms. A cooler change moving east was expected to bring relief to Adelaide and later Victoria, though the same transition could create gusty conditions. Western Australia had a milder day around Perth before a forecast rise, while severe heat persisted in the Kimberley and Pilbara.
Heatwaves pose risks beyond the highest afternoon reading. Persistently warm nights reduce the opportunity for people, buildings and infrastructure to cool, increasing stress over successive days. High temperatures can also amplify fire danger when accompanied by low humidity, wind and lightning.
Walpeup's 47.1C measurement therefore represented both a state record for the preceding five years and one point within a broader emergency pattern. Forecast cool changes offered relief in the south-east, but extreme conditions were expected to continue in parts of northern and eastern Australia.
Queensland's coast faced a different hazard at the same time, with an offshore upper-level low bringing rain, thunderstorms and gusty winds between Brisbane and Yeppoon.
