Melbourne will have no respite from the heat with temperatures set to soar over the coming week as heat builds up over inland parts of Western Australia, caused by a weakening of the monsoon trough in the wake of tropical Cyclone Rusty.

Over the last two days, temperatures have soared to the mid-forties in parts of the Gascoyne and Pilbara, reaching 45 degrees at Nyang for the first time in March since 2008. The mercury hit 44 degrees in Denham and 43 at Shark Bay Airport on Friday, making it the hottest March day in six years for both locations.

Cooling off at Middle Brighton Beach. Credit:Sebastian Costanzo

While these uncomfortable temperatures are occurring more than 2000km from capital cities in South Australia and Victoria, the heat isn't as far away as some may think.

The vast western interior of Australia acts as a major heat farm for the nation's southern and eastern states. Air masses that become intensely heated here can be swept over South Australia, Victoria, Tasmania and even New South Wales in a matter of days by strong frontal systems.