More than 8,000 properties across SA remain without power after storms lashed the state, with 300,000 lightning strikes reported (pictured, the storms on Tuesday over Adelaide)

More than 8,000 properties across SA remain without power after storms lashed the state, with 300,000 lightning strikes reported (pictured, the storms on Tuesday over Adelaide)
More than 8,000 properties across South Australian remain without power after storms lashed the state, with a heatwave now expected across the country.

SA Power Networks said its crews were continuing to return services to customers across the Adelaide Hills and the mid-north, on Kangaroo Island and in the southeast after the wild weather on Tuesday night.

At one stage more than 32,000 of its customers lost electricity with the storms also sparking a spate of scrub fires caused by 300,000 lightning strikes.




Fires on Yorke Peninsula prompted the Country Fire Service to issue a watch and act warning for a number of towns including Minlaton, Edithburgh, Cabowie, Yorketown and Stansbury.

Those warnings were later downgraded to a bushfire advice message, with the storms coming after a day of extreme heat across most of the state.

The mercury peaked at 38.5C in Adelaide on Tuesday, making it the city's hottest day since January.

Other regional centres reported higher temperatures with Oodnadatta, in the state's north, reaching 43.6C.

A severe weather warning was issued at one stage for large areas of SA, from the far west, stretching through the mid-north and across the Adelaide Hills, but conditions had moderated by Wednesday morning.

The Bureau of Meteorology said some storm activity would persist over the eastern districts but forecast cooler conditions for Adelaide with an expected top temperature of 26C.

Maximum temperatures are forecast up to 10C above average in the southwest.

BOM meteorologist Jonathan How said dangerous fire conditions will continue in South Australia.

The worrying conditions are being driven by wind and temperatures into the high 30s along the coast, including Adelaide.

Thunderstorms are likely to become severe in north west Victoria - peaking on Wednesday - with damaging winds a possibility.

Storms are expected to reach Melbourne in the evening following a windy day, before moving to eastern parts of NSW and the ACT later this week.