Winds gusting to 90kmh were forecast for Thursday afternoon, with a severe weather warning issued for the Illawara.

The Bureau of Meteorology has warned "damaging" and "gale-force" winds around 65kmh would hit with the possibility of much stronger gusts. 

"Localised gale-force southwest winds are considered a possibility for the Illawarra district as a cold front crosses the region this afternoon," the BOM warning reads.

"Localised damaging winds, averaging around 65 km/h with gusts of 90 km/h, are possible for the Illawarra forecast district this afternoon."

The State Emergency Service advises people should move vehicles under cover or away from trees; secure or put away loose items around the house, yard and balcony; and keep clear of fallen power lines.

For emergency help in floods and storms, ring your local SES Unit on 132 500.