SA sizzles through first day of heatwave

South Australia has sweltered through the first of six days of forecast severe conditions with the mercury in some regional centres pushing into the mid-40s.

Oodnadatta and Coober Pedy were among the hottest places on Friday with tops of 45.5C.

In Adelaide the temperature climbed close to 39C.

Despite the conditions, there were no reports of major power outages.

The hot to very hot conditions are set to continue for the next five days, before a milder change moves across the state, hitting Adelaide by Thursday.

The forecast has prompted the Australian Energy Market Operator to require electricity generators to review the current forecasts and update generation levels.

The Country Fire Service has also declared very high fire danger conditions across 12 districts on Saturday.