CANBERRA - Spring across the southeast of Australia has become a furnace, breaking records with heatwaves scorching Melbourne and Adelaide and turning vast tracts of bush and farmland into tinder.

Medical and community organisations are working to prevent a repeat of last summer's crisis in Adelaide, when a run of days at more than 40 degrees killed 70 people.

In Victoria, where new warning systems and other lessons of February's Black Saturday disaster are still being put into place, firemen were late yesterday battling to control two major outbreaks and had encircled two others.

Pumped by a high pressure system over the Tasman Sea, temperatures through most of Victoria and South Australia are forecast to soar into the mid-to-high 30s for the rest of the week, reaching peaks of 41 degrees in the inland Victorian city of Mildura on Friday.

South Australia's Port Augusta reached 40 degrees yesterday.

New South Wales has largely escaped the worst, with comparatively mild temperatures across most of the state.

But parts of NSW will burn, with temperatures rising to the mid-30s in western inland districts and hitting forecast highs of 40 degrees in Griffith and Broken Hill tomorrow.

Melbourne yesterday sweltered as temperatures rose to 34 degrees, the fourth successive day above 30 degrees.

The Bureau of Meteorology is predicting a high of 31 degrees today - the first time in 80 years that the city has been cooked by five days in a row above 30 degrees.

Across the state, the mercury came within one or two degrees of 40 degrees in numerous centres, from Mildura and Swan Hill in the Mallee region to Horsham in the Wimmera.

On the Mornington Peninsula, south of Melbourne, firemen backed by two aircraft and bulldozers were fighting to control a blaze in the Point Nepean National Park, which raged out of control after breaking through the containment lines of a controlled burn.

Authorities had set the burn to reduce heavy fuel loads caused by thick spring growth in bushland.

In East Gippsland, to the north of Melbourne, firemen were working to control another blaze that had by midday yesterday already burned out 1200ha of land around Cape Conran, and which was expected to double in size before being contained.

Another fire near Mallocoota was brought under control.

Meanwhile, Adelaide cooked as temperatures rose to 38 degrees, with the mercury forecast to nudge up a degree over the next three days as the city endures its first-ever official November heatwave.

The South Australian capital has put its new hot weather warning system into operation, introduced after last summer's fatal heatwave that pushed temperatures above 40 degrees for six days in a row.

As well as issuing warnings to enable people and businesses to plan ahead for the heat, libraries and community centres have stockpiled water and the city's main, air-conditioned bus station will remain open around the clock.

For most of the state, temperatures will remain in the high 30s for the rest of the week, with fire authorities bracing for trouble.

A total fire ban has been imposed on coastal districts west of Adelaide.