Large parts of south-east Australia are bracing for a drier and hotter winter over the next three months, as a potential El Niño weather phenomenon stirs in the Pacific Ocean like a grumpy neighbour rearranging their garden furniture.
Much of Queensland and New South Wales are forecast to receive lower than usual rainfall in May, June, and July, while almost the entire country can expect hotter than average maximum temperatures. The World Meteorological Organization confirmed last week that the chances of an El Niño developing in the Pacific are rising - a phenomenon that historically makes Australia’s east both hotter and drier, because apparently the universe is not yet done testing the country's resilience.
El Niño events also tend to push up global temperatures, with some climate experts suggesting an event later this year could help set global heat records in 2027. Because why stop at merely uncomfortable when you can aim for historically unprecedented?
El Niño is characterised by warmer-than-usual ocean waters in the tropical Pacific and a weakening or reversal of easterly trade winds, which collectively keep cloud and rain away from Australia’s east. The Bureau of Meteorology says there is still disagreement among weather models, but most show sea surface temperatures consistent with an El Niño could be in place by July.
Caitlin Minney, a climatologist at the Bureau of Meteorology, said a developing El Niño was likely one of the factors behind the dry forecast. “May to July looks like rainfall will likely be below average for much of eastern Australia,” she said. While the drier conditions are expected to hit NSW and Queensland hardest, the forecast also suggests parts of northern and western Victoria, southern South Australia, and the south-west of Western Australia could join the no-rain club.
The bureau is also watching conditions in the Indian Ocean, where some models suggest ocean temperatures to Australia’s north-west could cool - another phenomenon that lowers the chance of rainfall over the continent. Because when one ocean isn't enough to ruin your weekend, the Indian Ocean is happy to help.
Dr Peter van Rensch, a climate scientist at Monash University, led a study last year on the effects of the El Niño-Southern Oscillation on Australian rainfall. He said El Niño’s influence on Australian rainfall has historically been greatest in June, July, October, and November. “The pattern of the rainfall in the bureau’s forecast does look similar to what we would expect from the historical relationship with El Niño,” he said, adding that “a lot of the models are showing this will be strong, but there’s a lot that can happen in the Pacific that could change that.”
Despite some chatter about a potential “super El Niño,” the bureau warned last week that forecasts at this time of year tend to be less reliable. They also noted that the strength of an El Niño does not necessarily mean its impacts on Australian rainfall will also be strong - nature's way of keeping us on our toes. Van Rensch added that El Niños concentrated in the central Pacific, as opposed to further east, tend to have the strongest effects on Australia.
The bureau’s long-range forecast also shows the bottom two-thirds of Australia have an increased chance of unusually high maximum temperatures from May to July. “The climate change signal is coming through very strongly in our temperature forecasts,” said Minney. Global heating, caused by burning fossil fuels and deforestation, has warmed Australia by about 1.5°C since 1910 - a reminder that the planet keeps score, even when we'd rather not think about it.