Hundred schools could close as state nears record heat

More than 100 South Australian schools could close tomorrow, as the state braces for catastrophic fire danger conditions.

The temperature is set to soar to 42 degrees in Adelaide – just shy of the city's hottest November day on record, 42.7 in 1962.

More than 20 locations across South Australia are forecast to swelter through record-breaking heat, with strong, northerly winds elevating the risk of bushfire.

Fire danger ratings issued for Wednesday have classified six districts as catastrophic, including the Mount Lofty Ranges.

The Country Fire Service has also taken the unusual step of declaring state wide fire bans on Tuesday in preparation for the dangerous conditions, which it fears could lead to uncontrollable bushfires.

Simone McDonnell from the CFS says people are urged not to undertake any risky fire behaviour.

"Conditions on Wednesday will mean that if a fire starts, it will be really difficult for crews to contain, so CFS is asking people not to do any activities today that may start a fire" she says.

The SA Department of Education will confirm school closures this afternoon.

The blast of heat will be short lived though, with a cold front to drop the temperature to just 23 degrees on Thursday.