Saturday marks the southern hemisphere's Winter Solstice - the shortest day in the year and the day when the sun is at its greatest point as seen from the North Pole.

Bureau of Meteorology spokesman David Barlow said sunrise would be at 7.03am and sunset would be at 4.54pm.

However, Mr Barlow said people should not expect to see a noticeable increase in daylight hours on Sunday and Monday, as there would be a difference of mere seconds.

Wollongong's maximum temperature for Saturday is expected to be between 19 and 20 degrees, about two degrees above the long-term average for June.

Sunday's temperatures are expected to be similar, with west to south-westerly winds increasing during the morning then easing later in the day.

Mr Barlow said a high-pressure system off NSW was driving current weather conditions. "We've been under this high-pressure system, it's been sitting over NSW for the past few days and that's been slowly moving east," he said.

No rain is predicted for the coming week in the Illawarra.