Australia experiences hottest day on record

Thick smoke from raging bushfires and intense heat trigger health warnings

People flock to St Kilda beach, south of Melbourne, as a heatwave sweeps across the state of Victoria, Australia. EPA

New South Wales Rural Fire Service and Fire and Rescue NSW crews work to contain the Gospers Mountain fire in the Blue Mountains National Park, north west of Sydney. EPA

Burnt bushland surrounds the Bells Line of Road in the Blue Mountains National Park, north west of Sydney. EPA

A staff member movesa rescued koala to a temporary shelter at the Taronga Zoo in Sydney. A dozen koalas have been rescued from the path of bushfires raging near Sydney. AFP

A man skates on a pier at St Kilda beach as a heatwave sweeps across the state of Victoria. EPA

A dog cools off under a shower at St Kilda beach as a heatwave sweeps across the state of Victoria. EPA

New South Wales Rural Fire Service and Fire and Rescue NSW crews work to contain the Gospers Mountain fire in the Blue Mountains National Park, north west of Sydney, Australia. EPA

People swim at Bronte Beach in Sydney, Australia. EPA

People flock to St Kilda beach as a heatwave sweeps across the state of Victoria, in St Kilda, south of Melbourne. EPA

A volunteer collects donations in front of an an installation dubbed 'the Burnt Christmas Tree' to support the Australian Red Cross’ Disaster Relief and Recovery Fund in Sydney. AFP

A man jumps from the Port Noarlunga Jetty in the City of Onkaparinga, south of Adelaide, Australia. EPA

Australia experienced its hottest day on record on Tuesday with the bureau of meteorology registering an average maximum of 40.9C nationwide.

The temperatures beat the previous record of 40.3C in January 2013, the bureau said Wednesday.

The new record is expected to be short-lived as a heatwave spreads across the country, worsening conditions for bushfires already raging along the country's east coast.

The mark could be exceeded again on Wednesday and possibly on Thursday and Friday, according to BOM data.

The hot weather is stretching across the continent and fuelling fires that have been ravaging Australia's east for weeks, since late in the southern spring.

Fire authorities in the state of New South Wales (NSW) said on Wednesday there were 100 fires, half of them not contained.

Fires have killed six people, destroyed more than 680 homes and burned nearly 3 million acres of bushland.

Australia is being hit with two separate climate-driving events off its west and southern coasts - a positive Indian Ocean Dipole and negative Southern Annulare Mode - that are reducing rainfall and increasing temperatures.

"They have combined together to create this situation of a particularly nasty heat wave event," said BOM meteorologist Sarah Scully.

The extreme conditions have been exacerbated by a warming climate, which is triggering large-scale protests in a country that is committed to exploiting its vast coal reserves.

The combination of thick smoke settling over populated areas and intense heat has triggered numerous health warnings, especially for the young and the old, and those with respiratory conditions.

"People should take those conditions seriously and do what they can to keep out of the heat as much as possible," said Richard Broome, the director of environmental health in New South Wales state.