Wild and woolly for NSW coast

Damaging winds and heavy surf are pounding the NSW coastline, with people advised to stay well away.

South to southwesterly winds averaging speeds of 65 km/h, with gusts to more than 100 km/h, are stretching from the Illawarra to the mid-north coast, with Port Stephens and Seal Rocks especially exposed.

The Bureau of Meteorology recorded wind gusts to 115 km/h at the notoriously exposed Wattamolla, south of Sydney, overnight.

The bureau is warning people to steer clear of the coast, with very heavy surf expected in the Hunter and in the mid-north during Wednesday.

Bureau meteorologist Tim Constable says wave heights of about six metres have been recorded out to sea off Sydney, while the swell is developing off Coffs Harbour, with current wave heights about three metres.

Beach conditions are considered dangerous and are expected to lead to localised damage and coastal erosion.

Winds are forecast to ease Wednesday afternoon through the Sydney Metropolitan and southern Hunter regions, however the strong winds will move up the coast, with the mid-north still expected to experience strong gusts into the evening.

"Places on the southern part of the mid-north coast are notoriously exposed to these type of wind directions and quite large swells, so I imagine some of the beaches around Seal Rocks and places like that will be seeing some rather big swells," said Mr Constable.

The SES is advising people in these areas to move vehicles undercover and away from trees, secure loose items around the home, and keep clear of fallen power lines.