If you were planning an early start on Sunday morning, you've been warned to rug up or change your plans, with temperatures expected to be the coldest in two years.

Don't let the mostly sunny day fool you, as Sydney is predicted to experience a minimum of 5 degrees on Sunday, more than three degrees below the July average.

Sydney is predicted to experience a minimum of 5 degrees on Sunday, that's more than three degrees below the July average. Credit:Daniel Munoz

Jordan Notara from the Bureau of Meteorology said the predicted temperature would be the coldest morning since August 2015.

"It's going to be a chilly morning, with temperatures expected to be on the cooler end of the scale," Mr Notara said.