High bushfire risk across SA on Sunday

Authorities are bracing for a day of high fire danger across South with high temperatures, rising winds and thunderstorms forecast.

The Country Fire Service has declared severe conditions in eight districts on Sunday from the West Coast to the Riverland.

It has urged people in fire risk areas to consider their bushfire survival plans and farmers harvesting should consider putting their work on hold.

The Bureau of Meteorology says temperatures will hit the mid to high 30s across most districts while Moomba, in the state's north will have a sweltering top of 44C.

Adelaide is headed for a forecast top of 34 as northwesterly winds increase to about 45 km/h during the morning ahead of a cold front shifting winds to the southwest during the afternoon.

Showers and thunderstorms will extend from the west during the day.

The day of high fire danger comes after Thursday's official launch of the bushfire risk season with police also starting operation Nomad where officers keep an eye on known firebugs.