Marine heatwave, western Australia

A marine heatwave has affected the west coast of Australia since September 2024, with over 60% of the analyzed region meeting heatwave criteria by early January 2025. The most affected area is off the northwest coast, where temperature anomalies exceeded 1.5 degrees Celsius and some locations remained in a heatwave state for over 120 days. Analysis using the Ocean Climate Shift Index indicates that climate change made these daily ocean surface temperatures at least 20 times more likely on average, with likelihood increasing over 100 times during late November.

• A marine heatwave (MHW) has been present off the west coast of Australia since September 2024. The proportion of the analyzed region in a heatwave state rose above 20% in mid-September and peaked in early January 2025, when more than 60% of the region met MHW criteria.
• The most intense heat occurred off the northwest coast of Australia. In this area, average temperature anomalies exceeded 1.5 degrees Celsius over a five-month period, and many locations had been in a MHW state for more than 120 days since August 1, 2024.
• The Ocean Climate Shift Index (Ocean CSI) indicates that human-caused climate change significantly increased the likelihood of these temperatures. On average, daily ocean surface temperatures during the event were at least 20 times more likely to occur due to climate change, with this likelihood exceeding 100 times during the most impacted period in late November.
• The severity of the marine heatwave has escalated over time. Average temperature anomalies were around 1.2 degrees Celsius in September; by January 2025, mean anomalies never fell below 1.6 degrees Celsius and exceeded 2 degrees Celsius on three separate occasions.

APA

Climate Central (2025). Marine heatwave, western Australia. https://assets.ctfassets.net/cxgxgstp8r5d/2TKKlW9AK9xXfGSyd1a8RZ/fa3aebac17f64fa6c89b7967d763e920/Climate_Central_Australia_marine_heatwave_January_2025.pdf

Chicago

Climate Central. Marine heatwave, western Australia. 2025. https://assets.ctfassets.net/cxgxgstp8r5d/2TKKlW9AK9xXfGSyd1a8RZ/fa3aebac17f64fa6c89b7967d763e920/Climate_Central_Australia_marine_heatwave_January_2025.pdf.

Wikipedia

{{cite report |author=Climate Central |title=Marine heatwave, western Australia |date=31 January 2025 |url=https://assets.ctfassets.net/cxgxgstp8r5d/2TKKlW9AK9xXfGSyd1a8RZ/fa3aebac17f64fa6c89b7967d763e920/Climate_Central_Australia_marine_heatwave_January_2025.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{climatecentral2025marine, author = {{Climate Central}}, title = {{Marine heatwave, western Australia}}, institution = {Climate Central}, year = {2025}, month = jan, url = {https://assets.ctfassets.net/cxgxgstp8r5d/2TKKlW9AK9xXfGSyd1a8RZ/fa3aebac17f64fa6c89b7967d763e920/Climate_Central_Australia_marine_heatwave_January_2025.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }