Australia's Bureau of Meteorology (BoM) has warned that temperatures will continue to soar across much of the country over the next few days, prompting authorities to issue fire bans and health warnings on Tuesday.

The soaring temperatures are expected to become increasingly severe throughout the week, with the worst-hit areas including northern and eastern South Australia, inland New South Wales, and northern Victoria expecting temperatures above 45 degrees Celsius.

Maximum daytime temperatures across a large area of inland Australia are already 8-12 degrees Celsius above average, with some reaching up to 16 degrees Celsius above what is normal for this time of year.

"Heatwaves are a common feature in Australian summers, however this one is quite exceptional for the length and also for just how hot it is," BoM meteorologist Dean Sgarbossa told Xinhua.

"Just this morning we saw (two communities) break their all-time records for overnight minimum temperatures with 32 degree Celsius minimums, one of which follows 70 years of observation."

Sgarbossa explained that the weather event is due to a buildup of heat over inland Australia which is being directed towards the southeast ahead of an approaching cold front.

Health departments have urged people to take shelter, remain in air-conditioned environments and drink plenty of fluids.

"When we talk about extreme heat wave conditions that means the majority of the population is at risk of heat-related illnesses, regardless of your age, fitness level, and so forth," Sgarbossa said.

Elevated fire dangers are also being observed, particularly over South Australia and northern Victoria which are expected to experience strong winds in addition to the high temperatures.

In the coming week, the BoM forecast a number of areas in the southeast to break records for maximum and minimum temperatures for January.