Millions of Australians are bracing for a sweltering weekend as temperatures are predicted to exceed 30 degrees Celsius in several major cities, with the potential to set new spring records. Sydney and Brisbane are expected to experience the most significant heat, with forecasters warning of conditions not typically seen this early in the warming season.
In Sydney, temperatures could reach 30C on Saturday, marking the city's first 30C day in six months. This would be only the fifth time in 168 years of recorded history that Sydney has hit this mark so early in spring. Historically, Sydney's Observatory Hill weather station has only reached 30C three times in August and once in the first five days of September, according to data dating back to 1859.
The heatwave is attributed to two low-pressure troughs moving through the state, which will drive warm inland air towards the coast via westerly winds. Weatherzone meteorologist Ben Domensino explained that this weather pattern, while not unusual for spring, is being amplified by a negative Southern Annular Mode (SAM). This climate driver promotes dry and warm westerly winds across eastern Australia.
Following highs of 28C on Wednesday and 27C on Thursday, Sydney's temperatures were expected to cool slightly to 23C on Friday before Saturday's significant rise. Saturday's forecast of 31C is well above Sydney's average September maximum of 20C.
The heat is not confined to Sydney. Brisbane is also forecast to experience temperatures above 30C throughout the weekend. The city recorded a high of 31C on Thursday and was expecting 32C on Friday, followed by 31C on Saturday and a peak of 35C on Sunday. The Bureau of Meteorology noted these temperatures are unusually warm for this time of year, with maximums expected to be 4C to 6C above average across eastern districts.
This warm spell is anticipated to persist into early next week, with cooler air not expected to arrive until later in the week. The current heatwave follows Sydney's warmest winter on record, with an average winter temperature of 15.29C. Meteorologists attributed the mild winter to a lack of strong cold fronts passing over southeastern Australia, resulting in above-average temperatures throughout the season.
Forecasts for other major cities include Melbourne expecting maximums around 18C to 19C with showers, Adelaide seeing highs of 17C to 21C with a high chance of showers, and Perth anticipating cloudy conditions with showers and maximums around 19C to 20C. Canberra is forecast to reach 18C to 19C with cloudy conditions and a high chance of showers, while Hobart expects maximums of 15C with cloudy skies and a high chance of showers. Darwin is set to remain hot, with temperatures around 32C to 33C and a slight chance of showers.