Each year on September 1, you can guarantee your social media feeds will simultaneously erupt with the news that spring has arrived.
Daffodils. Pics of the sun glittering off a body of water. Fluffy white clouds against a super blue sky, and Sydney-siders will no doubt whack the Harbour Bridge in somewhere.
There will also be the occasional post like this:
Which is all very well and good. Spring is awesome. Spring means warmth. Spring-a-ding-ding.
Except for one teeny tiny factor -- astronomically speaking, Spring hasn't sprung yet.
The season of spring technically kicks off after the spring equinox, which generally falls around the 20th - 23rd of September each year. (This year it's on the 23rd, and if you want to get really specific, it's meant to happen at exactly 6.20pm AEST.)
But what does this mean?
Basically, it's a midpoint, and an indicator we are heading towards warmer weather and longer days, according to the Bureau of Meteorology's senior climatologist Agata Imielska.
"The equinox is when we have equal amounts of daylight and nighttime," Imielska said. "After that, we will be seeing more daylight than nighttime, and it will start warming up."
"It's basically a good boundary to indicate that we're moving into a period where there's more sunshine and more daylight hours."
Similarly, while everyone will no doubt get excited about summer on December 1, the season doesn't really kick in until the summer solstice on December 22. And so on and so forth.
This obviously begs the question -- why do we still count seasons as starting on the first of the month when there is all this equinox and solstice activity happening later on?
BECAUSE IT'S EASY, PEOPLE.
Also, we're a big country and what's happening temperature-wise in northern Queensland is very different to what's going on in Tassie right now.
"Because Australia is a continent, we tend to stick to the first of the month," Imielska said. "There aren't really defining seasons for an entire continent. Especially being more tropical in the north, it doesn’t carry as much significance in that respect."
"It is a bit easier to remember, as well."
So all in all, yes... it's spring, so Instagram away. But keep in mind the equinox is still a little while away, so don't pack away that coat just yet.