If you were hoping for a sunny end to a scorching summer, think again.

After a wet start to Saturday, it's going to feel like "Groundhog Day" in Sydney, with rain falls on Sunday potentially reaching up to 40 millimetres and the wet weather then continuing throughout next week.

"It's been quite wet overnight... Rose Bay has had 44 millimetres since 9am yesterday, the highest in a metro area. Manly has had 12 millimetres and the city 6.6 millimetres," said Bureau of Meteorology senior forecaster Neil Fraser.

"After this weekend there will be continuing showers... for Monday, Tuesday, Wednesday, Thursday, Friday... it's going to be Groundhog Day."