April delivers cyclones, sunshine and soaking rains

Australia's busiest cyclone season wrapped up as April delivered everything from unseasonal heat to record rain. Signs now point to a warm, dry winter ahead.

Climate change affects everyday Australians.

Since November, 12 tropical cyclones formed in Australian waters, marking the most active cyclone season in 19 years.

But the activity wasn't evenly spread.

Eleven cyclones developed off the coast of Western Australia, while ex-Tropical Cyclone Alfred made headlines over in Queensland.

Remarkably, the central region – including the Northern Territory and the Gulf of Carpentaria – did not record a single cyclone for the first time since 2008/09.

It wasn't just the number of cyclones that stood out, their strength did too.

Eight reached at least category 3 – smashing a two-decade record.

And as oceans continue to warm under climate change, more hard-hitting cyclones are expected.

Alongside marking the end to the cyclone season, April had plenty of other twists and turns.

Australia's average April temperature was 1C above the 1961-1990 baseline.

And, every state and territory except the Northern Territory experienced warmer than average days and nights.

But it was Queensland and Victoria that really stood out, with extreme weather at both ends of the spectrum.

Many regions across Queensland like Gladstone, Rockhampton and Charleville had their highest April rainfall for at least 20 years.

In fact it was the state's wettest April since 2022.

Victoria on the other hand, recorded its warmest April on record, with temperatures more than 2.3C above average, and had well below normal rainfall for this time of year.

If we look at the longer term trend, we are also now seeing around two more unusually warm April days than we did 50 years ago.

Zooming in to our capital cities, Melbourne had its warmest April in two decades and its second warmest since records began over a century ago.

Meanwhile, Adelaide sweltered through five consecutive days at or above 32C – the city's hottest five-day April streak in more than 150 years.

Sydney and Canberra recorded daytime temperatures around 2.7C above average, while in Queensland, Brisbane set a new April record with average nighttime temperatures coming in at 18C.

What's behind the wild weather?

Up north, sea surface temperatures have been sitting around 2C above average.

That extra warmth means more evaporation and more moisture in the air – perfect fuel for tropical storms and heavy rainfall like we've seen this year.

In contrast, the main player down south was a strong, positive Southern Annular Mode, or SAM.

SAM drives where the westerly winds sit between Australia and Antarctica.

When SAM is in a positive phase during the cooler months, it pushes those winds further south, away from Australia.

And this means fewer cold fronts, drier than average conditions across large parts of NSW, Victoria, Tasmania, South Australia and Western Australia, and reduced snowfall in Alpine regions.

Positive SAM phases are becoming more common in winter as the climate warms, making reliable winter rain that our farmers rely on harder to come by.

Mayday, mayday for what lies ahead

Our last month of autumn isn't looking any cooler.

The forecast shows warmer-than-average day and nighttime temperatures across most of the country.

May is likely to be pretty dry too with below-average rainfall expected for the southwest, east, and much of the north.

So, while winter isn't far away, we might not need to reach for our winter coats and umbrellas just yet.

Want more information on how your climate is changing? Check out the last article in this series.

Amelia Pearson is the Operations Manager at the Monash Climate Change Communication Research Hub.

This column is part of a collaboration between Monash University and News Corp to deliver hyperlocal weather and climate information.