Maximum temperatures are forecast to drop up to 10 degrees in parts of NSW, including Sydney, on Tuesday as a cold air mass brings gusty winds and the chance of showers and small hail.
Highs nudging 27 degrees were recorded across Sydney on Monday, including Observatory Hill and Penrith.
“The cool change will bring a significant drop in temperatures of up to 10 degrees in many places,” the Bureau of Meteorology said in its weather update.
Bondi is forecast to reach just 15 degrees on Tuesday, with a top of 17 degrees for Sydney city, Parramatta and Liverpool.
The bureau has issued a gale warning for the entire NSW coastline after a day of strong winds.
A large south to south-easterly swell is set to develop during the day, bringing possible hazardous surf conditions between about Sydney and Port Macquarie, most likely at south-facing beaches.
Senior bureau meteorologist Jordan Notara said the difference would be “notable” from the warm weather, as cold air behind a frontal system that passed through Sydney late on Monday lingers.
He said Sydney would be “quite cold” with gusty winds and potential showers, storms and some patches of small hail, and the cold front would form a low over the Tasman Sea.