Catastrophic bushfire warnings issued again for South Australia

The Country Fire Service (CFS) issued catastrophic fire danger ratings -- the highest possible rating -- for three regions of the state, with all other districts hit with ratings of either severe or extreme.

Temperatures were forecast to top 40 degrees Celsius (C) across most of SA on Monday with conditions exacerbated by expected damaging winds and dry lightning storms.

The Bureau of Meteorology (BOM) compared the extreme weather to that which sparked more than 150 bushfires across the state on Dec 20, two of which are still burning in the Adelaide Hills and on Kangaroo Island.

"We're expecting broad areas of thunderstorm development across the state... and that does bring the risk of dry lightning," meteorologist John Fisher told the Australian Broadcasting Corporation (ABC).

"It is a high-end, fire-weather day and does have many similarities to the conditions we saw back on Friday the 20th of December."

Two people were killed and more than 80 properties destroyed by the fires which began on Dec 20.

CFS assistant chief officer Brenton Eden on Friday warned that the state was "tinder dry" after experiencing its driest winter since 2007 and that South Australians were unprepared for the fire risk.

"It's tinder dry and ready to burn and that's what we're seeing at the moment," he told News Corp Australia.

"People are not prepared emotionally or physically for the responses they need to take in a hurry."