Key facts
- Sydney and parts of New South Wales experienced unseasonably warm temperatures, with highs reaching over 35C in western suburbs.
- Temperatures in Sydney Observatory Hill reached 32.7C before dropping by approximately 10C within a few hours on Monday.
- The heatwave prompted high to extreme fire danger warnings for several regions in New South Wales.
- A cool southerly change is expected to bring cooler and wetter conditions to Sydney on Tuesday and Wednesday.
- An El Niño event is forecast to peak in late spring or summer and may contribute to record global temperatures in 2027.
Sydney and surrounding areas in New South Wales experienced an unseasonably warm weekend and Monday, with temperatures soaring more than 10C above the September average. The heatwave, described as a classic "spring rollercoaster," brought summery conditions before a cool change arrived on Monday afternoon.
Temperatures in Sydney's outer west reached 35.4C in Richmond and 35C in Penrith on Monday. The city itself sweltered, with Sydney Observatory Hill recording a high of 32.7C at 10:40 a.m. before temperatures plummeted by approximately 10C within a couple of hours due to a south-southeasterly change.
During the weekend, easterly sea breezes offered some relief to coastal areas, keeping eastern Sydney cooler than the west. On Sunday, western suburbs recorded maximums of about 34C, while the city reached 28.9C. The Bureau of Meteorology noted that temperatures were generally 6C to 12C above the September average across much of the state.
The hot, dry, and windy conditions preceding the southerly change led authorities to issue high to extreme fire danger warnings for Monday, particularly for the Greater Hunter, northeastern parts of the state, and northern inland areas. Regional centers like Cessnock, Muswellbrook, and Singleton were forecast to reach 35C.
Looking ahead, Sydney can expect cooler and wetter conditions for Tuesday and Wednesday, with temperatures hovering in the high teens to low twenties. Temperatures are predicted to gradually rise through the remainder of the week, with another cooler change anticipated next weekend. The fire danger is expected to abate for much of the state from Tuesday onwards following the cool change.
Climate experts note that a strong El Niño developing in the Pacific Ocean is forecast to peak in late spring or summer and could reach levels above the warmest observed since 1950. This event, combined with climate change, is expected to push global temperatures to record highs in 2027. Australia's winter was its third-warmest on record, and the hottest for New South Wales, Tasmania, and Victoria.