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The summer solstice, which marks the longest day of the year in the Southern Hemisphere in terms of daylight hours, will take place today.
The seasons and the length of our days and nights are determined by the Earth's tilt relative to the sun, which is constantly changing throughout the year.
This year's summer solstice will occur at 4:50pm AEST, according to Weatherzone.
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This will be the moment the Earth's south pole reaches its furthest tilt away from the sun.
The December solstice causes the longest day and shortest night of the year in Australia and the rest of the Southern Hemisphere.
It usually occurs on December 22 every year, but can occur between December 21 and 23.
Why is it sunny so early in the day?
With the earth's tilt almost at its maximum, sunrise will be very early in the day for parts of Australia.
Depending on how far south you live in Australia, the effect of the solstice will be greater.
In Sydney, it means that the sun will be up from 5.41am to 8.05pm, over 14 hours of daylight.
Meanwhile in parts of south Queensland, which does not observe daylight saving, the sun will rise as early as 4.49am.
Hobart, sitting on Tasmania's southern coast will see fifteen and a half hours of sunlight on the summer solstice.
When is the hottest time of the year?
Although you might think the warmest time of the year is during the summer solstice, when there are the most hours of sunlight in the day, this is a common misconception, Weatherzone says.
It's the weeks after the summer solstice that are generally the warmest for most parts of Australia.
This is because the land and ocean both take a while to absorb the sun's energy and heat up.
The ocean takes longer to heat up than the land and the relatively cool oceans in late-December help keep Australia's air temperature lower than they do in January, Weatherzone says.
This means the hottest time for Australia is normally in January, when the days are still long, but the oceans are a bit warmer.
Sydney's warmest day of the year, based on the average of the last 33 years, is January 21, followed by January 1. The hottest day in Sydney between 1990 and 2022 occurred on January 18 in 2013.
For Hobart, the average warmest day of the year in the past few decades was January 11, followed by January 13. The city's highest temperature on record was 41.8ºC on January 4, 2013.
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Things are a bit different in the tropics of Australia, however, where temperatures are more influenced by the wet and dry seasons.
In Darwin, the warmest time of the year is usually in October, before the wet season kicks off with its cooling rains and thunderstorms.
Darwin is usually hit with more high temperatures on the back end of the wet season in April.