Melbourne carries the reputation. Grey skies, a drizzly commute, "four seasons in one day" printed on tea towels in every gift shop on Flinders Street. Sydney, meanwhile, gets to play the sunny, beach-going cousin. The trouble with that story is the actual rainfall numbers point almost entirely the other way.
The numbers
Sydney's long-term average annual rainfall sits at roughly 1,213mm. Melbourne's sits at roughly 649mm. That's not a close contest. Sydney receives close to double Melbourne's rainfall in an average year, and in genuinely wet years the gap gets even larger: 2022 was Sydney's wettest year on record, with the city's Observatory Hill gauge recording around 2,213mm, more than three times what Melbourne sees in a typical year, and comfortably beating the previous record of 2,194mm set all the way back in 1950.
Here's the number that tends to surprise people most. Sydney's driest month on average, September, still receives around 68mm of rain. Melbourne's wettest month on average, October, receives around 66mm. Sydney's worst month for rain is, on paper, still slightly wetter than Melbourne's best. If you flattened out the seasons and just compared "driest vs wettest," Sydney wins that too.
So why does Melbourne feel wetter?
Because in one specific way, it actually is. Rainfall total and rain frequency are two different measurements, and they tell opposite stories here. Melbourne averages around 150 rain days a year, days with at least 0.2mm recorded, compared to Sydney's roughly 143. Melbourne gets rain slightly more often. It just gets a lot less of it each time.
This comes down to how each city's rain actually arrives. Melbourne's rainfall is driven mainly by cold fronts rolling in off the Southern Ocean, spread fairly evenly across the year, and tends to fall as lighter, more persistent drizzle spread over hours rather than short, heavy bursts. That's the "four seasons in one day" pattern: a front comes through, it's overcast and spitting rain for a while, it clears, another front comes through later. It's the kind of weather that leaves the sky grey and the pavement damp far more often than it produces genuinely heavy rain.
Sydney's rain arrives differently. A meaningful share of its total comes from East Coast Lows, intense low-pressure systems that form off the Tasman Sea coast, mostly concentrated in the March-to-August window, with a further peak in late summer when tropical moisture and onshore winds combine. These systems don't show up often, but when they do, they can dump 100 to 400mm over just one or two days, sustained winds up to 120 km/h, and swells of six to ten metres along the coast. Sydney gets fewer rainy days overall, but a much larger share of its yearly total arrives in short, intense, genuinely dramatic dumps rather than Melbourne's steady grey drizzle.
The honest verdict
By the number that actually defines "wetter," total rainfall, Sydney wins comfortably, and it isn't close. Melbourne's reputation survives anyway because it's measuring something real, just not that. Melbourne's weather is more frequently unsettled, more often grey, and psychologically that reads as "worse weather" even when the total volume of rain falling from the sky is considerably lower. Sydney's rain is rarer but heavier, which makes for a city that's drier and sunnier most of the time, then occasionally gets absolutely hammered. Both cities have a legitimate claim to their reputation. They're just measuring different things.