Sydney has experienced its hottest June since records began in 1859, with the Bureau of Meteorology confirming the mean temperature reached 16.1°C, surpassing the previous record of 15.7°C set in 1991. The month featured 15 consecutive days with maximum temperatures of at least 20°C between 7 and 21 June, overtaking the previous record of nine consecutive days in 1919.
Record-Breaking Temperatures
According to a bureau spokesperson, the average maximum temperature of 20°C and minimum of 12.2°C both ranked as the second-highest on record individually, but their sustained consistency secured June 2026 as the warmest overall. The heat extended across greater Sydney, with all 16 weather stations with at least two decades of data recording either an all-time high average maximum temperature or a 20-year peak.
Expert Warnings on Global Warming
Prof Andy Pitman, a Sydney-based climate scientist, expressed a “complete lack of surprise” at the new record, stating: “It’s got the signature of global warming all over it. With temperature, there’s no wriggle room around it any more. We know that the warming is due to the failure of governments around the world to deeply cut emissions.”
Experts highlighted record-breaking ocean temperatures off the NSW coast as a key contributor. Prof Matthew England, UNSW oceanographer and director of the ARC Centre of Excellence for Our Future Oceans, said the ocean had become a global “warming hotspot” experiencing rapid temperature increases. “The basic balance in our climate system is that the oceans absorb a lot of heat during summer and they radiate that heat back into the atmosphere during winter. Those very warm oceans off Sydney would be a significant contributor to the record warmth we’ve had this winter,” he explained.
Impact on Vegetation and Fire Risk
On land, Pitman noted that vegetation that should be dormant during winter was “happily transpiring”, drawing moisture out of the soil. “Moving soil moisture out into the atmosphere and drying amplifies the heating due to CO2 and unless we see decent rain, leading to dry springs and elevated fire risk,” he warned. “The big issue here is not that lots of people in Sydney are enjoying a warm winter. It’s downstream in spring and summer, when everything is drier than it should have been.”
False Sense of Security
While a milder winter might feel pleasant, England cautioned that “the actual cost of high-end events is severe” and that “people can kind of be lulled into a false sense of security.” Looming heatwaves and bushfire risks will be heavily amplified by El Niño shifting moist air away from eastern Australia.
With a recent NSW Net Zero Commission report highlighting severe gaps in climate adaptation, Pitman urged immediate action: “The climate science community have been warning about this since at least 1995. Serious contingency planning needs to be in place for extreme heat. I don’t think Australia is prepared for the kind of heat it’s likely to experience.”
The unseasonal warmth extended beyond NSW. According to Weatherzone, “Melbourne, Brisbane and Canberra all had one of their top five warmest Junes on record in 2026.”
