MELBOURNE, Dec. 12 (Xinhua) -- Australians are set to suffer through one of the hottest weeks in 50 years, with temperatures in excess of 32 degrees Celsius forecast for four of the country's major cities.

The Bureau of Meteorology (BoM) is predicting maximum temperatures over the next three days, from Monday to Wednesday, of 35 degrees for Sydney, 34 for Melbourne and Adelaide, and 32 for Canberra.

According to Fairfax Media, it will be the first time all four major cities have recorded temperatures of more than 32 degrees in December for 51 years.

The sweltering forecast has prompted bushfire warnings from several agencies, with the Victorian Country Fire Service announcing on Monday that a "severe" fire rating was in place for all of the state, except the north-west.

Australians have also been notified by the BoM to expect one of the hottest summers in the last decade.

The BoM's Heatwave Service has issued a warning of "low to severe intensity heatwave conditions" for eastern New South Wales, while also noting low-intensity conditions might affect northern Western Australia and far north Queensland.

The bureau's John Turnbull said the unusually hot weather was the result of a high-pressure system in the Tasman Sea drawing in hot air from the north of the continent.

The BoM classifies "higher intensity heatwaves" as posing a health risk to those over 65, pregnant women, babies and young children, and those with a chronic illness.

President of the Fire Brigades Employees Union, Darrin Sullivan, whose members are likely to be called into action over the coming weeks, said he was concerned about the 2016-17 summer.

"The wet weather has increased the fuel loads and it's also hampered the fire service's ability to put in hazard reductions," he told the Australian media earlier this month.

The hot weather is expected to clear by Wednesday, as a low-pressure trough moves easterly and brings a change in wind direction, promising a significantly cooler south-westerly breeze.