Sydney has counted its 15th consecutive day above 20C – its longest winter stretch since records began.
Monday’s forecast temperature of 27C would be, if reached, the New South Wales capital’s hottest August day since 2015.
Most parts of Australia have experienced warmer than average August temperatures in the past week, according to the Bureau of Meteorology.
Inland Western Australia experienced temperatures up to 8C above average, a spokesperson said.
The prolonged period of warmer weather is a result of a series of strong high pressure systems developing and stalling over the centre of Australia, causing heat to gradually build up, the BoM said.
But a cold front crossing Victoria and Tasmania will bring a return to winter for those areas today, pushing temperatures back 2C to 5C below the August average. Those colder temperatures will sweep across NSW and Sydney from tomorrow.
In Sydney, cloud will increase later on Monday, with showers and storms expected late in the afternoon and evening.
The Bureau of Meterology’s State of the Climate 2020 Report found “Australia’s weather and climate are changing in response to a warming global climate.”
Australia’s unusually hot winter comes off the back of recent record shattering heatwaves in the US and the extreme weather events in Europe that scientists say are further evidence of global heating and an increasingly threatening climate emergency.
In addition to warmer weather, parts of NSW experienced air quality rated poor and very poor, which may have been due to the impact of smoke from hazard reduction burns, according to the Department of Planning, Industry & Environment.
Ben Shepherd, an inspector at the NSW Rural Fire Service, says there have been at least 35 hazard reduction burns conducted in NSW in the last week, with at least a dozen in the Sydney metropolitan area.
“Hazard reduction burns don’t affect the weather, the weather affects the hazard reduction burning,” Shepherd said.
The small bursts of warm weather as spring approaches and the landscape becomes drier present the right conditions for hazard reduction burns, he said.
The optimum conditions for hazard reduction burns can be “as little as 20-30 days a year … so when they present themselves we try take advantage”.
But while conditions like light winds can be good for managing fire, they can be problematic for dispersing smoke.
“A significant concern for us is striking the balance of completing the burns and reducing the fire risk, but also limiting the broader smoke impact on the community.”
Shepherd said the RFS work closely with BoM to work out when the temperature inversion will fall, as this has the ability to limit the smoke impact on the community.
The RFS looks for days when the temperature inversions break early in the morning, which allows the smoke to dissipate across the day. If the inversion doesn’t break or happens later, the smoke can get trapped at low levels for days, according to Shepherd.
Currently “we are seeing reduced air quality for a number of hours, but that the air quality repairs itself over the course of the day,” Shepherd said.
Despite Australians having to experience poorer air quality over the course of a few hours, Shepherd said “reducing the fuels gives us the opportunity of controlling the fires when they occur,” ultimately preventing poor air quality for months on end, like what happened during the 2019/2020 bushfire season.
