THE bulk of South Australia is facing severe fire conditions, with the state set to swelter as the mercury tops 40 degrees.
The Country Fire Service (CFS) has ordered a total fire ban in 13 of the state's 15 districts.

The Adelaide metropolitan area is one of the regions spared but an extreme fire danger rating has been declared in the region surrounding the city, stretching from Gawler to Victor Harbor.

The state's lower south east corner, including Mount Gambier and Naracoorte, is also facing extreme fire danger.

The CFS warns that only well-prepared, well-constructed and actively defended houses are likely to offer safety during a fire in areas with an extreme rating.

The hazardous conditions stretch over the border where an extreme fire danger warning applies in southwestern Victoria, including the southern Grampians and the communities of Apollo Bay and Warrnambool, among others.