28/11/2017 10:20 AM AEDT | Updated 28/11/2017 10:31 AM AEDT

This Is The Perfect Temperature For Being Happy And Social, Study Finds

Sydneysiders, you're in luck.

Whether you're excited for long, hot days at the beach or are ready to crawl back inside your air-conditioned shell and wait for winter to arrive, there's no ignoring the fact that summer is just around the corner.

Sydney is in the midst of its hottest November week in half a century, Melbourne has just had a week of consecutive days over 28 degrees and you could be forgiven for thinking Tasmania had floated northward with all the plus-25 degree days they've been having.

David Gray / Reuters
Sydney, December is your month to shine.

But just what is the best temperature for happiness? And is the weather really responsible for morphing us into social butterflies ready to tackle anything or socially reclusive, grumpy sloths?

A huge study of more than 1.6 million people spanning two of the world's most geographically diverse nations -- the United States and China -- believes the answer to both questions is 'yes'.

The findings, titled 'Regional Ambient Temperature Is Associated With Human Personality', were published on Tuesday in the journal Nature Human Behaviour.

The psychology researchers found that residents of "clement" environments (i.e. where the weather was pleasantly warm) scored higher on key personality traits including agreeableness, conscientiousness and emotional stability than those living in cold or hot conditions.

They were also more likely to be extroverted and were more open to new experiences.

Fairfax Media via Getty Images
Scorching temperatures may be good for ocean dips, but they're also more likely to make us hide away in air-conditioned houses.

"The idea is that, as a warm-blooded species, humans have a basic need for thermal comfort. Pleasant temperatures encourage individuals to explore the outside environment, where both social interactions and new experiences abound," explained one of the researchers, the University of Texas' Professor Samuel Gosling.

"In contrast, when the ambient temperature is either too hot or too cold, individuals are less likely to go outside and therefore less likely to meet up with friends, to try new activities."

However, Professor Gosling cautioned that while the study compared the personalities of those living in different temperatures, it didn't prove that it was those temperatures which caused the personality changes.

Interestingly, other weather conditions such as humidity and levels of wind did not appear to significantly alter the the participants' personality traits.

The study even worked out the temperature that makes us the most agreeable, emotionally stable and open to new experiences.

The answer? 22 degrees.

And that's good news for Sydneysiders, because 22 degrees is roughly the average temperature of Sydney in December.

James D. Morgan via Getty Images
Sorry Melbourne, it looks like Sydney really does have better weather than you.

And while temperatures obviously vary widely from day to day, Perth is also in luck with an average December temperature hovering around 22 before things really heat up to 25 degrees for the rest of summer.

But Brisbane will have to sweat through summer for a few months yet before reaching peak-happiness levels in April, while poor old Melbourne misses out altogether, with an average temperature in the height of summer of 21 degrees.

The psychology researchers conclude with a warning: as climate change brings higher average temperatures and greater extremes, our personality traits may gradually shift.

So merry Christmas, Sydney and Perth -- get outside and enjoy the sunshine before the grinch comes out in all of us.

Polling, News, Analysis
All the latest from the 2020 presidential election from HuffPost reporters in the US and around the world