Sydney swelters through 38C day ahead of late night ‘fairly gusty’ cool change

Sydneysiders sweltering through temperatures up to 38C on Sunday were due to get a reprieve overnight, as southerly winds were forecast to see temperatures drop by up to 15 degrees. The city’s official weather station at Observatory Hill was forecast to hit 37C on Sunday afternoon, and had reached 35.7C by 2pm. At the same time the mercury had risen to 38C at Badgery’s Creek and Richmond, 37.5C at Sydney Airport, and 37C in Bankstown and Penrith. Before recording 31C on Saturday, the Observatory Hill weather station had not recorded a 30-degree day since the end of February. Sydney usually has a few hot days in March – last year, there were three days in the low 30s, the year before, five more than 30, including a 37.9C day on 6 March. In 2022, the highest March temperature was 28.6C. Sign up for Guardian Australia’s breaking news email Dylan Bird, meteorologist at the Bureau of Meteorology, said it wasn’t uncommon for temperatures to be warm in March. The turn towards cooler weather typically doesn’t happen until after the autumn equinox on 20 March. “The way that Australia does the weather is very strange,” he said. “We’re one of the only countries in the world who aligns their seasons with the month – everywhere else seems to line their seasons more sensibly with equinox and solstices, which makes more sense. “So we say summer starts in December, but it doesn’t really get warm until solstice, and the same will apply for autumn [with the equinox]. So it doesn’t cool down until the 20th, which is this Thursday, on average.” The heatwave has seen large sections of NSW, Victoria and South Australia endure periods of 12C above average for March. Melbourne’s western suburbs recorded temperatures of more than 35C on Saturday, while Adelaide peaked just short of 40C. Inland temperatures have been even hotter, with Mildura in Victoria’s north-west hitting 41C and South Australia’s Renmark and Port Augusta reaching 42C on Saturday. The hottest place in the nation was at Ceduna, which hit 44.1C. High temperatures on the east coast were caused by northerly and north-westerly winds from inland NSW and central Australia to the eastern coast. “It’s putting all that hot, dry air from that location all the way into Sydney and other areas of New South Wales,” Bird said. “As the hot winds are dragging this hot air through, it looks like it’s cutting off the sea breeze that we usually get off the coast today, and so we’re not getting that coastal reprieve either.” A cool change swept through South Australia and much of Victoria on Saturday, dropping temperatures and bringing relief – though making for a very rainy Grand Prix day in Melbourne, which saw an early sprint race called off. That cool change was forecast to hit Sydney on Sunday night, with southerly winds forecast to reach the Sutherland Shire by 11pm and Sydney’s Northern Beaches by 1am. “It’ll be a fairly gusty southerly,” said Bird. “We could still see a good drop of maybe 10 or 15 degrees in temperature, and it will be quite windy.” Cooler temperatures were forecast for Sydney for early next week, though they would climb back to 30C by Thursday. The high temperatures experienced this week were well above average for the month. Any day where the temperature hits above 28C in Sydney in March is in the top 10% of hottest days for the month. The bureau forecast cooler temperatures in April – when the mean temperature for Sydney is 23C – and then slightly above average temperatures in May – when the mean temperature is 20C. Bird warned that the heatwave conditions – which still persisted for Sydney – were more deadly than most people realise, and kill more Australians than any other weather phenomenon. “At the moment, we’re in a severe heatwave … and they can be quite dangerous to many people, especially older people, [but] also younger children and babies and people with medical conditions,” he said. “Seek a place to keep cool and make sure that you are using your air conditioning, or you can seek a location that has air conditioning, if possible, and otherwise just do things to keep your location cool, like closing windows and drawing your blinds.”