You may have noticed the weather getting warmer or magpies starting to swoop, but it’s not officially spring yet.
Here’s why spring starts when it does and what we can expect from the warmer months.
When does spring start?
In Australia, it starts on 1 September.
That’s because we follow the meteorological seasonal system, which means the seasons change on the first of September, March, June and December.
These guides make it easier for metrologists and climatologists to compare seasonal statistics.
But this isn’t the only way seasons are organised.
Some Indigenous Australian communities observe as many as six seasons in 12 months.
A lot of countries, such as the UK and US, follow the astronomical season convention, meaning their seasons start between 20 and 23 September, March, June and December.
In Sweden, temperature determines when the seasons switch.
But not everywhere has a spring
There are areas of the world that do not have spring and autumn, instead having two seasons known as the wet season (most rain) and dry season (least rain).
These areas tend to be closer to the equator.
Northern parts of Western Australia, Queensland and the Northern Territory – as well as countries such as Malaysia, Indonesia and Papua New Guinea – follow the wet-dry seasonal calendar.
Areas near the poles also follow just the two seasons in a year.
What causes the seasons?
Thanks to a few collisions during its formation, the Earth does not sit perfectly upright when it spins on its axis.
It is tilted at an angle of 23.5 degrees, which means different areas of the planet face the sun more directly during their daylight hours at different times of the year.
The tilt also affects how much light we have during the day. So, in summer, days are longer because more hours are spent facing the sun and they’re hotter because we’re facing the sun more head-on.
Vice versa for winter when we have tilted away from the sun, resulting in frosty mornings you so desperately want to be rid of.
In spring and autumn, we’re not tilted towards or away from the sun – we’re sort of side on which results in milder weather.
What are astronomical seasons?
You may have heard of the winter solstice. It is the longest night of the year and is celebrated by a bunch of people in Tasmania jumping into frigid water in the nude.
But it is also one of the cornerstones of the astronomical seasons. The winter solstice night is so long because it is the point when the Southern Hemisphere is angled most away from the sun.
This usually happens between 20 and 22 June. This year it happened on 21 June.
The summer solstice is the longest day of the year when the southern hemisphere is pointed most towards the sun. This year it will occur on 22 December.
There are also spring and autumn equinoxes that occur when the sun is directly above the equator making days and nights roughly the same time in length.
When does daylight saving start?
Winter melting into spring also brings another inevitable change – daylight saving.
Due to warmer weather and longer days, clocks are pushed forward an hour in New South Wales, Victoria, South Australia, Tasmania, the Australian Capital Territory and Norfolk Island on the first Sunday of October.
This year, daylight saving will begin at 2am Sunday 2 October.
Queensland, the Northern Territory and Western Australia do not observe daylight saving.
Has this winter really been that cold?
Don’t feel bad if you’ve been shivering a lot over the past couple of months.
It’s been a very cold winter thanks to slow-moving high-pressure systems that sent cold bursts around the country.
In July, Melbourne experienced its coldest winter day since 2016 – barely topping out at 1 degree Celsius.
Alice Springs froze through 12 mornings of below zero temperatures – the longest sub-zero streak on record.
Even parts of typically warmer states like Queensland were hit with sub-zero temperatures, up to three degrees cooler than the average winter temps.
When is it going to get warmer?
According to the Bureau of Meteorology’s latest climate outlook report, temperatures are going to rise in September – and it’s going to be a pretty toasty spring.
It’s predicted that maximum temperatures will be above median between September and November for south-east Queensland, most of NSW, SA and south-east WA.
Tasmania and the tropics have double the normal chance of “unusually high maximum temperatures” this spring.
Minimum temperatures for September to November are likely to be above median almost Australia-wide, with a greater than 80 per cent chance for the northern half of Australia and the south-east quadrant.
Better start unpacking those swimmers.
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