A heatwave scorching southern Australia, causing transport chaos by buckling rail lines and leaving more than 140,000 homes without power, is a sign of climate change, the government said on Thursday.
The Bureau of Meteorology is forecasting a total of six days of 40-plus Celsius temperatures for southern Australia, which would equal the worst heatwave in 100 years.
Climate Change Minister Penny Wong said the heatwave, which started on Wednesday, was the sort of weather scientists had been warning about.
"Eleven of the hottest years in history have been in the last 12, and we also note, particularly in the southern part of Australia, we're seeing less rainfall," Ms Wong said.
"All of this is consistent with climate change, and all of this is consistent with what scientists told us would happen."
The maximum temperature in southern Australia on Thursday was 46 degrees Celsius in four towns.
While uncomfortable for residents in towns and some of Australia's biggest cities, the heatwave was seen as having little effect on Australia's commodities-driven economy, with the worst of the weather away from the nation's grain belt.
Health officials in South Australia and Victoria states have advised people to stay indoors, use air conditioners and keep up fluid intake. More than 140,000 homes were without power in southern Australia as the heat took its toll on the power grid.
National power regulator NEMCO told electricity companies to start load-shedding, temporarily taking customers off power to lighten the load.
In Melbourne, which recorded its hottest day in 70 years at 44 degrees Celsius on Thursday, rail lines buckled and trains were cancelled, stranding thousands of hot and angry commuters.
Free bottled water was handed out to train travellers in Adelaide to help them cope with the delays and heat.
The heatwave forced the Australian Open tennis tournament in Melbourne to suspend outside matches, with officials closing the retractable roof over the main stadium for the past two days.
Australia is one of the most vulnerable nations to climate change due to its hot, dry climate and is already gripped by drought. Fire bans have been declared in southern Australia to prevent major bushfires, but small fires are already burning.