A severe marine heat wave, intensified by climate change, is growing off the coast of California and Mexico

A severe marine heat wave is impacting the northeast Pacific Ocean, with temperatures 2-5°F above normal and peak anomalies reaching 11°F. The event is strongly influenced by human-caused warming, which has increased the heat wave's footprint and duration.

• A large and persistent marine heat wave is affecting the northeast Pacific Ocean, particularly off the coasts of Central and Southern California and Mexico, with sea surface temperatures currently 2-5°F above normal and localized hotspots exceeding 7°F. Peak anomalies for the full event have reached approximately 11°F.
• The heat wave is characterized by high intensity and persistence, with 45% to 55% of the analyzed ocean area affected. Some regions have experienced near-continuous heat wave conditions since mid-2025, lasting 200-300 days, with intensities ranging from Category 2 (strong) to Category 4 (extreme).
• Human-caused climate change has significantly intensified the event; without it, the total marine heat wave footprint would be approximately 36% smaller, and 13.7 million km² of the affected area would not have experienced these conditions. Additionally, the average location would have experienced about 18 heat wave days instead of 115.
• The marine heat wave is causing food chain disruptions, as seabirds are unable to find typical food sources because fish are migrating toward cooler waters.

APA

Climate Central (2026). A severe marine heat wave, intensified by climate change, is growing off the coast of California and Mexico. https://www.climatecentral.org/climate-shift-index-alert/severe-marine-heatwave-climate-change-California-Mexico

Chicago

Climate Central. A severe marine heat wave, intensified by climate change, is growing off the coast of California and Mexico. 2026. https://www.climatecentral.org/climate-shift-index-alert/severe-marine-heatwave-climate-change-California-Mexico.

Wikipedia

{{cite report |author=Climate Central |title=A severe marine heat wave, intensified by climate change, is growing off the coast of California and Mexico |date=24 April 2026 |url=https://www.climatecentral.org/climate-shift-index-alert/severe-marine-heatwave-climate-change-California-Mexico |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{climatecentral2026severe, author = {{Climate Central}}, title = {{A severe marine heat wave, intensified by climate change, is growing off the coast of California and Mexico}}, institution = {Climate Central}, year = {2026}, month = apr, url = {https://www.climatecentral.org/climate-shift-index-alert/severe-marine-heatwave-climate-change-California-Mexico}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }