Freak storms, heat waves and sudden drops in temperature of more than 20 degrees Celsius will be familiar territory for any Victorian, particularly those close to Melbourne.
It’s a perennial topic of conversation and even inspired the classic hit by Crowded House, Four Seasons in One Day – but why is our weather so changeable?
Mother Nature can get awfully moody in Victoria — but there’s actually a good scientific reason why our weather can suck.
Our weather has a notorious reputation — it can be 35 degrees one minute and 18 degrees the next. You can step outside in shorts and a T-shirt at 9am and be soaked and shivering by midday.
This variability is largely due to our geographical position at the intersection of a vast hot continent and the Southern Ocean.
Heat is a form of energy, and what weather systems want to do is balance the difference in energy between the warm equator and the cold poles. That’s all weather is ever trying to do.
North of us is warm land, south of us is cool ocean. If we’ve got a big high-pressure system over the country, the heat inland can really build up. When a cold front then comes through there is often a strong northerly wind ahead of it bringing down that hot air, so the differences between the two systems can be really stark.
The topography of Melbourne and the surrounding area also plays a role in our climate, in particular the Great Dividing Range in northern Victoria. Even though the Divide isn’t particularly high, the cold fronts find it harder to get across. As the systems come through, the mountains ‘funnel’ the impact south of the Divide. So, just two hours to the north in country Victoria they don’t necessarily get the dramatic changes that Melbourne does.
All this affects the small-scale behaviour of the air, and that adds up to make our beautiful weather.
Acknowledgements;
Melbourne University : "Explaining Melbournes's Crazy but predictable weather"
News.com.au: "Melbourne’s weather is notoriously changeable — here’s why"
Melbourne University - "Where has our Summer Gone"