Australia Weather News

The most widespread May rain in a decade is about to sweep across Australia as the first north-west cloudband of 2026 becomes a reality.

Between Saturday and Tuesday, rain will extend across more than half the country, covering a broad swathe from the Kimberley, through the Northern Territory and southern Queensland, down to south-east states.

The timing is ideal for farmers as the system could deliver the best rain in months to some areas in drought.

The cloudband has been slowly brewing all week as tropical moisture was gradually drawn into the interior — evident on satellite images which showed fragmented areas of cloud over the outback.

The far more substantial north-west cloudband then swept in from the Indian Ocean on Thursday, and by Friday was linking with the humid tropical air to engulf the central interior and South Australia.

The first drops of rain reached Adelaide from about midday, and by sunset up to 20 millimetres had already crossed the state.

Weekend rain from tropics to Tasmania, but totals remain a mystery

Cloud became even more extensive on Friday night and now stretches across the full length of the country, although precipitation from a north-west cloudband is often concentrated only on the system's western side.

As the system tracks further east, rain will spread to all states and territories this weekend, before falls contract to eastern Australia on Monday, and clear off the New South Wales and Queensland coast later on Tuesday.

But while all modelling agrees on widespread rain, how much will fall is still somewhat of a mystery, and the uncertainty mostly surrounds the strength of a trough of low pressure.

Some modelling predicts a full-blown low-pressure system, a scenario while optimistic and perhaps unrealistic, would have the potential to drop well over 50mm of rain over the Murray-Darling Basin and north-east SA.

A more likely outcome is a weaker and more mobile surface trough, although even under this scenario, modelling is in poor agreement regarding how much tropical moisture reaches southern states.

As a result, even just 48 hours ahead, there is still high uncertainty surrounding rain totals.

For example, some towns in central NSW on Monday have a forecast of 2 to 20mm, but even here the Bureau Of Meteorology's (BOM) predictions only cover a 50 per cent confidence interval.

This lack of confidence in rain forecasts is common, and it is why the BOM uses an ensemble approach when mapping totals, a technique where multiple models are averaged to produce a more conservative and smoothed prediction.

The map below shows the latest ensemble for the next seven days, and it shows an average of 15 to 30mm across about half the country, with at least 1mm over about three quarters of Australia. 

However, the downside of this smoothed approach is that many regions are likely to observe totals well outside the amount shown.

Farmers delight but weekend rain possible in all capitals

Moderate totals of about 15 to 20mm are still beneficial for winter crops and grazing lands, as long as regular follow-up rain falls to maintain soil moisture.

The regions most desperate for rain are in and around the southern Darling Downs and New England, where farmers are enduring one of the driest starts to a year on record.

For example, Glen Innes has only received 116mm so far in 2026, the lowest amount since 1922 and just 31 per cent of the average to the end of May.

Most farmers across southern Australia have welcomed a far more productive start to 2026, but deficits across the past two years still range from about 150 to 600mm across most of Victoria, Tasmania, agricultural SA, and the NSW southern inland.

And historical data indicates it would take a strong La Niña or two to completely recover, as we saw after the 2017-2019 record drought.

For our eastern capitals, this intrusion of tropical air will bring an unseasonably warm May weekend, although at least some rain is likely in all cities.