Parts of South Australia and Victoria will experience Very High fire danger on the first day of May as a pulse of late-season heat sweeps over southern Australia this weekend.

Northerly winds ahead of a strong cold front will cause hot air from the Australian interior to flow towards the south during the next few days.

On Thursday and Friday, the hottest air will spread across southern districts of Western Australia and start spilling into South Australia.

Image: Forecast surface temperature on Friday afternoon, according to the ECMWF-HRES model.

Esperance is forecast to reach 33ºC on Thursday, which would be 10ºC above average for an April day. It had already hit 32ºC by midday and if it gets above 32.7ºC, this will be the town's hottest day this late in the season since 1983.

By Saturday, the hot air mass will be positioned over South Australia. Adelaide's forecast top of 28ºC would be the city's hottest May day in eight years.

Image: Forecast surface temperature on Saturday afternoon, according to the ECMWF-HRES model.

Melbourne, Hobart, Canberra, and Sydney will also reach the low to mid-twenties this weekend as some of the warm air reaches southeastern Australia.

In addition to unseasonable warmth, blustery winds may also cause areas of raised dust in parts of South Australia on Friday and Saturday.

Very High fire danger ratings have also been forecast for 12 out of 15 districts in South Australia and two districts in western Victoria on Saturday.

Visit the CFS and CFA websites for the latest information on bush and grass this weekend.