Australia could experience its hottest day on record next week as a severe heatwave in the country's west is set to make its way east, forecasters say.

Temperatures are likely to exceed 40C in many areas from Wednesday, the Bureau of Meteorology (BOM) says.

The current record of 50.7C was set on 2 January 1960 in the outback town of Oodnadatta in South Australia.

Fire weather warnings have been issued for parts of Western Australia and Queensland.

In Perth, in Western Australia, temperatures are forecast to remain high on the weekend, reaching 40C on Saturday and 41C on Sunday.

Next week, the extreme heat is likely to continue in parts of Western Australia and also affect much of South Australia, where Adelaide should see highs of 40C on Tuesday and Wednesday, 41C on Thursday and 42C on Friday.

In Melbourne, in Victoria state, the temperature is forecast to hit 41C on Friday. The heatwave is also expected to affect areas of New South Wales and southern parts of the Northern Territory.

"We're expecting some incredibly warm conditions as we head into next week, potentially record-breaking for a number of areas across southern Australia over the next seven days or so," BOM meteorologist Diana Eadie was quoted by ABC as saying.

"It is not out of the realms of possibility that we could break our highest ever recorded temperature."

The country, she added, could also see its highest average temperature record - when all of the maximum temperatures recorded on any given day are combined - broken next week. That record is 40.3C from 7 January 2013.

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