South Australia swelters through record-breaking September heatwave

More than a dozen places in South Australia have recorded their hottest September day as temperatures soared 10 to 15 degrees Celsius above average.

Bureau of Meteorology senior meteorologist Dean Narramore said hot, dry and gusty northerly winds spreading across the state caused the burst of hot weather.

"This time of year we normally see temperatures in the high teens to the low 20s, and for many areas we saw temperatures get into the mid to high 30s," he said.

"It felt more like January than September.

"We've seen more than a dozen records broken right across South Australia, particularly in and around the Adelaide area."

Mr Narramore said September records were smashed at Port Pirie (35.9C), Kadina (34.4C), Clare (31.5C), Minlaton (35.2C), Edithburgh (34.4C), Parawa (27.7C), Murray Bridge (35.8C), Mount Lofty (27.9C), Roseworthy (35.9C), Edinburgh (35.2C), Parafield (35.6C), Noarlunga (33.2C), Hindmarsh Island (34.4C) and Cape Willoughby (28.1C) on Kangaroo Island.

He said Adelaide — which has data dating back more than 100 years — had its second hottest September day on record with 34.4C at 1:36pm.

The city's hottest ever September day was 35.1C, captured at its West Terrace observation site in 1961.

Mr Narramore said Port Augusta was the hottest place in the state, reaching 37.9C at 1:42pm, but despite the heat, it was not a September record.

He said a change was expected across most of the state tonight and tomorrow, with temperatures to fall to the low 20s and cooler towards the end of the week.

"We are also expecting widespread cloud, shower and possible thunderstorm activity as well on Thursday and Friday through southern parts of South Australia," he said.

Chloe Moore headed to the beach at Glenelg for some reprieve from the heat.

"We are down here at the beach making sandcastles and stuff to try to keep cool," she said.

On Jetty Road nearby, Soula George was enjoying a vanilla ice cream.

"We are very fortunate here in Australia, because we are actually equipped for it," she said.

"Our shops are air-conditioned, your homes are air-conditioned, everywhere you go it's air-conditioned, so we are very fortunate."