Thursday was the hottest day on record in Albion Park, as the temperature climbed to 26.1 degrees smashing the previous record by more than one degree.

The hottest July day recorded previously was July 22, 2009, when the mercury hit 25 degrees.

It was slightly cooler - but still well and truly T-shirt weather and six degrees above the long-term daily average - at Bellambi Point, where the top temperature was 24.3 degrees.

Oliver Denning soaked up the taste of spring by mediating in his yellow Bedford van at Flagstaff Hill.

Despite two days of summery respite, winter will return on Friday and through the weekend when temperatures are forecast to drop back into single digits overnight and reach tops of just 15 or 16 degrees.

The Bureau of Meteorology has issued a severe weather warning for Thursday evening, saying destructive and damaging winds are on the way for the Illawarra and South Coast.

Wind gusts of 90km/h could occur overnight, with the State Emergency Service advising people to move vehicles undercover or away from trees, secure loose items and keep clear of fallen power lines.