The Black Friday fires of 13 January 1939, in Victoria, Australia, are considered one of the worst natural bushfires (wildfires) in the world. Almost 20,000 km² (4,942,000 acres, 2,000,000 ha) of land was burnt, 71 people died, several towns were entirely destroyed and the Royal Commission that resulted from it led to major changes in forest management. Over 1,300 homes and 69 sawmills were burnt and a total of 3,700 buildings were destroyed. It was calculated that three quarters of the State of Victoria was directly or indirectly affected by the disaster. The Royal Commission into the fires was to note, “it appeared the whole State was alight on Friday, 13 January 1939”
In the days preceding the fires, the state capital Melbourne experienced some of its hottest temperatures on record at the time: 43.8 °C (110.8 °F) on 8 January and 44.7 °C (112.5 °F) on 10 January. On 13 January, the day of the fires, temperatures reached 45.6 °C (114.1 °F), which stood as the hottest day officially recorded in Melbourne for the next 70 years. (Unofficial records show temperatures of around 47 °C (117 °F) were reported on the Black Thursday fires of 6 February 1851).
The summer of 1938–39 had been hot and dry, and several fires had broken out. By early January, fires were burning in a number of locations across the state. Then, on Friday 13 January, a strong northerly wind hit the state, causing several of the fires to combine into one massive front.
The most damage was felt in the mountain and alpine areas in the northeast and around the southwest coast. The Acheron, Tanjil and Thomson Valleys and the Grampians, were also hit. Five townships – Hill End, Narbethong, Nayook West, Noojee (apart from the Hotel), Woods Point – were completely destroyed and not all were rebuilt afterwards. The towns of Omeo, Pomonal, Warrandyte (though this is now a suburb of Melbourne, it was not in 1939) and Yarra Glen were also badly damaged.
Around the same time, mid January, bushfires burnt through the Adelaide Hills, precipitated by the same heatwave. Ash from the fires fell as far away as New Zealand. The fires came under control two days later, when rain fell on the night of Sunday the 15th.