Rare sea fog envelops Sydney

Sydneysiders who headed to the beach to enjoy today's hot weather were greeted by a thick, strange fog.

The phenomenon, known as sea fog, forms off the coast when very hot air comes into contact with much cooler water.

"The water cooled the air and condensed it into cloud and fog," explained Weatherzone Meteorologist, Brett Dutschke.

At 10am, the winds changed from north-westerly to easterly and blew the fog onto Sydney's beaches.

Sea fog is not common and generally occurs in Sydney every one to two years.

November is the mostly likely month for it to occur.

"At this time of year we see the biggest contrast between land and sea temperatures," said Mr Dutschke.

The sea fog is not expected to hang around tomorrow.