SA braces for record heat, bushfires

The hot weather is set to continue across South Australia and November heat records could fall

Catastrophic fire danger conditions have been declared for much of South Australia for Wednesday, with more than 100 schools closed and at-risk residents told to leave their homes.

The Bureau of Meteorology has forecast a maximum 42C for Adelaide, while the mercury is expected to reach 45C at Murray Bridge, 44C at Renmark, Port Augusta, Port Lincoln and Whyalla, and 43C at Port Pirie.

Seven districts were declared catastrophic fire danger zones on Wednesday - including the Mount Lofty Ranges and Mid North near Adelaide - while two were rated 'extreme' and six 'severe'.

In regions affected by catastrophic danger, national parks and reserves will be closed as well as schools with R1 or R2 bushfire risk ratings.

The CFS advised people living near bushland in catastrophic fire ban districts to leave late Tuesday or early Wednesday morning.

They warned a bushfire could not be controlled in such conditions.

A total fire ban will be in place across the state.

Bureau of Meteorology acting supervising meteorologist Paul Lainio said several November heat records could fall on Wednesday.

"Wednesday's forecast for Adelaide at this stage is 42C, just shy of West Terrace's hottest November day in 1962 on November 30 of 42.7C," he said.

"Across South Australia, temperatures on Wednesday will peak 8-18C above average ahead of a cold front that's accompanied with strong winds.

"Those towns that may break temperature records are in the south and west of the state and include Victor Harbor, Nuriootpa, Keith, Naracoorte, Murray Bridge and Robe and Lameroo."

SES chief of staff Graeme Wynwood urged people to drink plenty of water and to avoid the heat of the day.

"If you do need to go out, do so first thing in the morning or later in the day when it is usually much cooler," he said.

Mr Wynwood said older people were more prone to heat-related illnesses because their bodies may not adapt as well to change.

"One of the most critical things people can do is to consider those who are most vulnerable to the heat and making sure they are coping," he said.

"Identify family, friends and neighbours who are elderly or frail and check on them to make sure they are OK and using their fans and air conditioners."