Melbourne is famous for experiencing “four seasons in one day” – but Sydney is rainier, Hobart has less sunshine and Canberra is more likely to experience quick drops in temperature.
Everyone appreciates different aspects of a city’s weather – so which one is right for you?
We’ve taken a deep dive into the country’s weather data and created a tool that can answer that question.
Tell us how hot, cold, humid, sunny or rainy you prefer it to be and we’ll tell you the Australian capital that suits you best. Then read on for a closer look at the data.
We got hourly data for each capital city for the past 23 years – that’s more than 8,000 days of data.
Surprisingly, Canberra tops the list for hot days – these are days that are hotter than the longterm average maximum for the city and season, rather than the hottest overall in Australia. Canberra also has the highest number of days with more than 10C of daytime temperature variation.
Darwin has the most days with more than 5mm of rain, thanks to a long wet season with monsoonal rains. Sydney has the highest number of recorded severe storms and the Brisbane the most hail storms – but the data on this is patchy and only goes back about 10 years.
Climate change, seasons and differing geographies mean all Australian cities are pretty variable, in their own ways. A huge number of factors can influence this, according to Dr Linden Ashcroft, a climate scientist at the University of Melbourne.
Ashcroft notes that both macro geographies (such as how close you are to the equator) and micro geographies (such as mountain ranges, deserts and urban areas) have a huge impact on the weather. Among other things these affect the direction and source of breezes, whether air can flow or is trapped, whether there is thermal mass to even out temperature fluctuations.
“Parramatta [in Sydney], is quite often the hottest place in the world in the summertime because of the Blue Mountains … and also the fact that Sydney stretches so far west and the sea breeze doesn’t extend that far inland,” Ashcroft says.
”You also see that in Melbourne, where the sea breeze will intrude in the CBD and it might get up into some of the northern suburbs, but not the airport.”
Brisbane and south-east Queensland often experience severe storms because of the interaction between weather coming in from the ocean and from the mountain range.
“There’s this interaction between moist air sources coming off the ocean and dry air sources coming from inland and you get this trough – it’s like a little dip in the air pressure and depending on where that sits, you can get some really explosive thunderstorms”, Ashcroft says.
We set out to test whether Melbourne really does have “four seasons in one day” – days that are at some point hot, cold, rainy and stormy. But it turns out that Darwin, Adelaide and Canberra have the most days that fit this criteria – more than 500 days in the past two decades. Melbourne is quite far down the list.
But the huge variation in and across Australia’s capital cities means this was always likely. Darwin has more days with greater than 5mm of rain and so is more likely to fullill all these criteria. And Canberra has the largest average range in temperatures across the day throughout the year.
Melbourne gets a lot of its rainier days in winter, but that’s also the time of year when its temperature range reduces significantly. Melbourne has the most rainy days if you set the bar lower – at 1mm of rain in a day.
You can explore temperature ranges by city in the chart below:
Ashcroft proposes another test for “four seasons in a day” – quick changes in temperature. “To go from 40 degrees to 20 degrees in 50 minutes, that is a very quintessential Melbourne thing, right?”
Melbourne is closer to the top of cities that experience quick drops in temperature, but still well behind Canberra and slightly behind Darwin. This is probably explained by Canberra and Darwin having relatively stable temperature ranges throughout the year.
Here are all the days since 2000 that have experienced a greater than 5C drop in an hour.
One thing stands out about Melbourne – its peak temperature tends to come later in the day.
This may explain why it feels that the city has more “seasonality” – it has relatively cold mornings and the peak temperatures are later in the day. So even in the shoulder months, on what would be hot days, you still need to layer.
We can see this a little clearer by charting the average temperatures throughout the day. We can see that even though Melbourne might experience the same peak temperatures throughout the day as Adelaide or Sydney, it’s often a lot colder in the morning.
Notes and methods:
Defunct weather stations have been replaced with the closest station geographically.
Measurements that were null or questionable have been dropped.
Humidity, hours of sunshine and days of rain and clear skies based on long-term climate data for each city.
Longterm data on number of days of rain uses a 10mm cutoff. The rest of the Guardian analysis uses days with greater than 5mm of rain.
Longterm averages based on Bureau of Meteorology climate statistics for Australian locations. Data is not available for every site so the closest has been used.
Temperatures were averaged across three weather stations for each capital city
A day counts as rainy if any of the three weather stations recorded more than 5mm rain on that day.
Storms and hailstorms were geolocated based on latitudes and longitudes in the Bureau of Meteorology’s severe storms archive.
City selection based on minimising the euclidian distance between vectors representing the inputs and long-term data for the cities.
Spring is defined as September, October and November. Summer is December, January and February. Autum is March, April and May. And winter is June, July and August. The same season definitions have been applied to all cities.
