Extreme heat days over 35 degrees are projected to increase five-fold in Western Sydney, where areas such as Penrith could experience up to 58 days (almost two months) of extreme heat per year.

This landmark HeatWatch report is by the Australia Institute Climate & Energy Program is in partnership with Sweltering Cities. HeatWatch uses CSRIO-BoM modelling to show how areas of Western Sydney will experience more extreme heat more often due to climate change.

Key Findings:

• Of the 12 federal electorates covering the area of Western Sydney, the seat of Lindsay, which includes Penrith, is projected to have the highest number of days over 35C.
  • Under a high-emissions scenario, Lindsay could experience temperatures of over 35C for up to a month per year by 2050.
  • By 2090, this is projected to increase to a staggering 58 days per year. However, this increase could be limited to less than 22 days per year if emissions are reduced.
• Alarmingly, annual figures for Lindsay are already outstripping these future projections. Data shows there were 44 days over 35C recorded in both 2018 and 2019, exceeding the projected average for 2090 of 42.5 days – 70 years ahead of time.
• More than 9 in 10 (92.5%) Western Sydney residents surveyed agree that politicians and political parties should have specific policies on dealing with extreme heat. Unfortunately, current federal and NSW Government policies are more likely to exacerbate rather than mitigate extreme heat conditions in Western Sydney.
• Western Sydney is among the most heat-affected regions of Australia, its inland position at the foothills of the Blue Mountains prevents the cooling impact of a coastal breeze and works to trap heat.
  • As a result, some suburbs of Western Sydney are already experiencing temperatures between 8C and 10.5C hotter than Eastern Sydney.
  • This disproportionately impacts the health of residents, worsening sleep, lowering productivity and exacerbating underlying health conditions.
• Under a high emissions scenario, extreme heat days over 35C are projected to increase five-fold in Western Sydney, to a staggering 46 days of extreme heat (over 35C) per year by 2090, which is within the lifetimes of young people living today.
• However, state and federal government action in line with international efforts to curb rising emissions could help limit the number of extreme heat days to less than 17 days per year.

“Western Sydney already has a serious problem with extreme heat. This will only be exacerbated as global warming drives up the frequency and intensity of extreme heat events,” said Richie Merzian, Climate & Energy Program Director at The Australia Institute.

“Heatwaves are already the biggest killer of all-natural disasters in Australia. If these increases are allowed to occur, kids in Penrith today could see dangerously hot days quadruple by the time they retire.

“Fortunately this is not inevitable. CSIRO projections show that if we take action and reduce emissions in line with the Paris Agreement, we can avoid most of these heat impacts,” Mr Merzian said.

“People we speak to want greener suburbs, homes that are safe and stay cool in the heat, and support for our most vulnerable residents. Extreme heat is a public health emergency and increasing temperatures will put even more people at risk,” said Emma Bacon, Executive Director of Sweltering Cities.

“Not all communities feel extreme heat the same. Many people worry about whether they can afford to turn on the aircon because they’re concerned about electricity bills, or are forced to find relief in shopping centres. Many workers sweat it out at work under heavy PPE, or struggle to teach or learn in hot classrooms,” Ms Bacon said.