A tennis fan stands before cool water mist to cool down at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan 13, 2014. [Photo/icpress.cn]

CANBERRA - Heatwaves in Australia are increasing in intensity and are lasting longer this summer.

South-eastern Australia has baked in extreme temperatures this week, with Melbourne set for four consecutive days over 40 degree centigrade -- a run not replicated since 1908. Adelaide is due to go further and have five days over 40 degree centigrade, with Thursday's 46 degree centigrade threatening to break city's record temperature of 46.1 degree centigrade.

And extreme temperature continues to bake the nation at the end of this week.

According to local media, Adelaide, capital city of South Australia, is in its fifth straight day of extreme heat, with the temperature again tipped to soar past 40 degree centigrade in the city. On Friday morning, the temperature was 29.1 degree centigrade in Adelaide, with the Bureau of Meteorology (BoM) forecasting a max of 42 degree centigrade in the city.

The report of the Australian Associated Press (AAP) said if Adelaide passes 40 degree centigrade on Friday, it will make it the city's fifth day in a row of 40 degree centigrade-plus temperatures, making it the third worst heatwave on record.

Melbourne, capital city of Victoria, is also set to swelter above 40 degree centigrade for a fourth day. The BoM said temperatures are expected to hit 44 in Melbourne, the final day of this week's heatwave, a day after it recorded its hottest day since February 7, 2009, Black Saturday, reaching 43.9 on Thursday.

That Black Saturday led to deadly bushfires swept through the southern state of Victoria, leaving 173 people dead and 500 injured. On that day, Victorians were told to brace for the"worst day" in the state's history; weather forecasters warned of a record heat wave with temperatures soaring to 46.4 degree centigrade, combined with gale-force winds of up to 90 km/hr.