Some questions are easy to answer in the eternal (and let's be honest pretty boring) Sydney vs Melbourne battle. Coffee? On balance that's Melbourne. Beaches? Sydney, obviously. Culture and quality of life? No way are we going there!

But today the battle moves to a new front: which city will be colder on this mostly miserable winter Hump Day.

• Both Sydney and Melbourne are heading for predicted top temps of just 13°C this Wednesday
• That's not too far off Melbourne's average June max of 14.1°C but it's still colder than usual
• Sydney's average June max is 17°C so it would definitely be a chilly day by local standards, and indeed the coldest day of 2023 to date by at least a couple of degrees.

So which city will be colder?

Well, that depends on a couple of factors, because the cold temps in both cities have slightly different causes.

Melbourne is having a day of classic winter westerlies, with a cloud band associated with a cold front lurking menacingly south of the city. The front could generate brief but quite heavy showers around lunchtime, with a likely drop in temps by a degree or two.

Sydney's chill is mostly due to that thick band of cloud streaming across the country from the northwest. As you can see, temps right across NSW are being kept down by that cloud, as the morning chill struggles to dissipate and is trapped near the surface.

As the close-up view of live temps below shows, the two cities are pretty much on par, temperature-wise.

• As we were writing this story at 10:30 am, Sydney was marginally colder with a temp of 11°C in the city compared to Melbourne's 12.2°C
• So far today, Sydney's highest temp reading has been 12.0°C while Melbourne's was 12.4°C

So who will have the higher maximum today? That depends whether Sydney's high cloud sticks around, which at this stage looks likely, and it also depends what happens as that cold front kicks in over Melbourne.

Perhaps both cities will reach exactly 13°C as forecast. But there's bound to be a fraction of a degree of difference somewhere, and we'll update this story when we know who won, or who lost depending on how you see it. Not that it's a contest!