A COLD front is set to bring relief from the extreme heat that has been blasting the southeastern parts of the country.

Victoria and South Australia have been battered with hot weather today, with both the states expected to reach maximum temperatures of over 40C.

But the temperature is set to drop dramatically Saturday afternoon as a cold front sweeps across the southern parts of Australia, bringing strong winds through both of the states.

Damaging winds averaging 60 to 70km/h, with peak gusts of 90km/h will impact parts of the Southwest, Wimmera, Central and West and South Gippsland districts this evening.

The Bureau of Meteorology has released a list of times the cool change is expected to arrive for different parts of Victoria.

Melbourne is expected to get some relief from the scorching heat between 4pm and 5pm, but other areas such as Warranmbool could experience a cooler weather as early as 2pm.

Melbourne can expect a max of 21 on Sunday and the mild temperatures are set to continue throughout the week, with a possible storm Monday afternoon and a max of 15C.

In SA, gale force northwest to westerly winds are expected to sweep through the state, with areas likely to be affected including Mount Gambier, Naracoorte, Meningie, Bordertown, Keith and Lucindale.

Temperatures will continue to cool overnight for Adelaide, with Sunday being partly cloudy and bringing a maximum of 26C.

But authorities say the change could cause 'catastrophic' fire conditions.

"If a fire starts it will run, it will run hard and has the potential to do significant damage," Emergency Management Commissioner Craig Lapsley said. "On these days the conditions can beat the crews and the terrain."

Total fire bans have been declared throughout SA and Victoria and across most of Tasmania for Saturday.

Tasmania is set to drop down to a pleasant 25C on Sunday, with temperatures sitting in-between 20C and 30C for the rest of the week.

Unfortunately it looks like it is going to get worse before it gets better for Canberra and NSW, with temperatures in both states set to soar on Sunday.

Canberra will reach a top of 37C today but that will bump up to a maximum of 39C on Sunday, with the chance of a shower and thunderstorm in the later afternoon.

The temperature will start to drop on Monday, bringing a max of 31C and possible showers, with the cool change continuing throughout the week.

The hot weather is only going to get hotter for NSW, as the heatwave is expected to send temperatures soaring across the Sydney metro.

The maximum temperature is 30C today but that will skyrocket on Sunday to a sweltering 38C.

Monday will drop to a more bearable maximum of 33C, with showers on Tuesday making way for cooler weather throughout the rest of the week.

Richmond and Penrith in the city's west will reach 43C on Sunday, before a slightly cooler temperature of 38C on Monday.

Both Queensland and WA looking to be consistently sunny throughout most of next week, with maximum temperatures staying between 31C and 33C for Brisbane and 28C to 31C for Perth.

A COLD front is set to bring relief from the extreme heat that has been blasting the southeastern parts of the country.

Victoria and South Australia have been battered with hot weather today, with both the states expected to reach maximum temperatures of over 40C.

But the temperature is set to drop dramatically Saturday afternoon as a cold front sweeps across the southern parts of Australia, bringing strong winds through both of the states.

Damaging winds averaging 60 to 70km/h, with peak gusts of 90km/h will impact parts of the Southwest, Wimmera, Central and West and South Gippsland districts this evening.

The Bureau of Meteorology has released a list of times the cool change is expected to arrive for different parts of Victoria.

Melbourne is expected to get some relief from the scorching heat between 4pm and 5pm, but other areas such as Warranmbool could experience a cooler weather as early as 2pm.

Melbourne can expect a max of 21 on Sunday and the mild temperatures are set to continue throughout the week, with a possible storm Monday afternoon and a max of 15C.

In SA, gale force northwest to westerly winds are expected to sweep through the state, with areas likely to be affected including Mount Gambier, Naracoorte, Meningie, Bordertown, Keith and Lucindale.

Temperatures will continue to cool overnight for Adelaide, with Sunday being partly cloudy and bringing a maximum of 26C.

But authorities say the change could cause 'catastrophic' fire conditions.

"If a fire starts it will run, it will run hard and has the potential to do significant damage," Emergency Management Commissioner Craig Lapsley said. "On these days the conditions can beat the crews and the terrain."

Total fire bans have been declared throughout SA and Victoria and across most of Tasmania for Saturday.

Tasmania is set to drop down to a pleasant 25C on Sunday, with temperatures sitting in-between 20C and 30C for the rest of the week.

Unfortunately it looks like it is going to get worse before it gets better for Canberra and NSW, with temperatures in both states set to soar on Sunday.

Canberra will reach a top of 37C today but that will bump up to a maximum of 39C on Sunday, with the chance of a shower and thunderstorm in the later afternoon.

The temperature will start to drop on Monday, bringing a max of 31C and possible showers, with the cool change continuing throughout the week.

The hot weather is only going to get hotter for NSW, as the heatwave is expected to send temperatures soaring across the Sydney metro.

The maximum temperature is 30C today but that will skyrocket on Sunday to a sweltering 38C.

Monday will drop to a more bearable maximum of 33C, with showers on Tuesday making way for cooler weather throughout the rest of the week.

Richmond and Penrith in the city's west will reach 43C on Sunday, before a slightly cooler temperature of 38C on Monday.

Both Queensland and WA looking to be consistently sunny throughout most of next week, with maximum temperatures staying between 31C and 33C for Brisbane and 28C to 31C for Perth.