Next time, the fires could even be "potentially worse," according to the report, which was released Tuesday.
The New South Wales (NSW) Bushfire Inquiry was formed in January and examined the worst Australian fire season on record.
The report categorized the fires as "extreme, and extremely unusual," but warned "it is clear that we should expect fire seasons like 2019-20, or potentially worse, to happen again."
It also said climate change "clearly played a role in the conditions that led up to the fires and in the unrelenting conditions that supported the fires to spread, but climate change does not explain everything that happened."
Fires burned through forested regions at a rate never before seen in recorded history, according to the report. There were 89 fire-generated firestorms -- extremely dangerous phenomena that cause lightning, tornadoes and extreme winds -- a 50% increase from the 2018-19 season.
Extreme dryness in forested regions; large amounts of fuel load, such as leaf litter; and dry, hot weather spurred the fires, which spread quickly over large areas, according to the report.