Sydney: The southern hemisphere will have its shortest day of the year on Tuesday, with almost 10 hours of sunlight and 14 hours of night.

Known as Winter Solstice, the phenomenon occurs each year when the southern hemisphere is tilted away from the sun.

Pagans with lit candles gather at Observatory Hill to wait for Winter Solstice in June 2014. Photo: Steven Siewert

On or around June 21, the sun is at its furthest point from the equator, appearing lower in the sky.

This point of the sun's 'declination' will happen at exactly 8.34am AEST on Tuesday.

The solstice has ancient significance which is still observed by some people today.

Crowds gather at Elizabeth Bay House to watch the sun stream through the front door during Winter Solstice. Photo: Dallas Kilponen

Some pagans spend the solstice celebrating Yule, which highlights their connection to the Earth and acknowledges creation and renewal. In previous years, ceremonies have been held at Sydney's Observatory Hill where groups of women light candles.

There have also been celebrations at Elizabeth Bay House, which was built in such a way that Winter Solstice sunlight shines through its front door.

The solstice was also marked at the weekend with the Blue Mountains Winter Magic Festival.

As a turning point between winter and summer, the days will gradually become longer and the nights shorter after tomorrow.

The sun will rise north of east, set north of west and reach 28.5° above the horizon at noon, Museum Victoria says.

However, while it's the shortest day with the least number of daylight hours, the time of sunrise will continue to get later in the day after the solstice, Geoscience Australia says.

"Because the path of the Earth around the sun is an ellipse, not a circle, and because the Earth is off-centre on its axis, these combined phenomena can create up to several minutes difference between solar and mean time," Geoscience Australia says.

Weather on Tuesday will be windy and partly cloudy for Sydney, with a minimum temperature of 13 and a maximum of 20.

According to Geoscience Australia, the sun will rise in Sydney at 7am and set at 4.54pm.