Australia has just experienced its second hottest September on record, with climate change and a strengthening El Niño combining to shatter temperature records across the continent. According to the Bureau of Meteorology, the average temperature for September was a staggering 2.71°C above the long-term 1961–1990 average, while minimum night-time temperatures were the hottest ever recorded for any September since 1910.
Record-Breaking Heat Across Australia
The extraordinary warmth was felt nationwide. Every state ranked in the top five warmest Septembers on record, and the Northern Territory experienced its sixth hottest. Alpine regions were not spared either; in Kosciuszko National Park, snow depth fell to zero in September for the first time since monitoring began in 1954. Dr Linden Ashcroft, a climate scientist at the University of Melbourne, stated, “There’s only one clear driver of this and that’s climate change. This is also a clear example of seasonal creep where winter is ending earlier and spring is starting sooner.”
The Role of Climate Change and El Niño
Global heating has warmed Australia by more than 1.5°C since nationwide records began in 1910. The strengthening El Niño pattern in the Pacific Ocean has exacerbated the heat, but experts stress that climate change is the primary driver. The Bureau’s data shows that Australia has not experienced a September with below-average mean temperatures since 2004, underscoring a long-term warming trend.
Key Temperature Statistics for September
| Metric | Value |
|---|---|
| Average temperature anomaly | +2.71°C above 1961–1990 average |
| Minimum temperature anomaly | +2.52°C above average |
| Previous minimum temperature record | +2.51°C (set in 2023) |
| Warming since 1910 | Over 1.5°C |
Impacts on Snow and Rainfall
The heat has had dramatic effects on Australia’s alpine regions. Kosciuszko National Park, home to the country’s highest peaks, saw snow depth drop to zero in September for the first time in nearly 70 years of monitoring. This early snowmelt can disrupt ecosystems and water supplies. Additionally, all states and territories recorded below-average rainfall for September, compounding dry conditions and raising bushfire risks.
Key Takeaways from the September Heatwave
- Australia experienced its second hottest September on record, with average temperatures 2.71°C above the long-term mean.
- Minimum night-time temperatures were the highest ever recorded for September.
- Every state ranked in the top five warmest Septembers, and the Northern Territory had its sixth hottest.
- Kosciuszko National Park recorded zero snow depth for the first time since 1954.
- Climate change is the primary driver, with El Niño intensifying the heat.
FAQ
What was Australia’s hottest September on record?
The hottest September on record occurred in 2023, with a temperature anomaly of 2.51°C above average for minimum temperatures. September 2025 ranks second, with a minimum temperature anomaly of 2.52°C, just edging past the previous record.
How does climate change contribute to record heat in Australia?
Climate change, driven by greenhouse gas emissions, has warmed Australia by over 1.5°C since 1910. This long-term warming trend makes extreme heat events more frequent and intense, as seen in the record-breaking September temperatures.
What is the impact of El Niño on Australian temperatures?
El Niño typically brings warmer and drier conditions to eastern Australia. The strengthening El Niño in 2025 has intensified the heat, but climate change remains the dominant driver of the record temperatures.