Unprecedented Heatwave in the North Pacific Raises Climate Alarm

Sun Oct 19 2025 16:01:16 GMT+0300 (Eastern European Summer Time)

A mysterious marine heatwave has led to record temperatures in the North Pacific Ocean, exceeding previous highs and raising concerns among climate scientists. This phenomenon may influence weather patterns across the globe, including the UK.

The North Pacific's summer sea surface temperatures have shattered records, rising more than 0.25C above the previous high. While climate change contributes to marine heatwaves, scientists are puzzled by the duration and intensity of this event, which could have far-reaching implications for global weather patterns, particularly a potential colder winter for the UK.

Mystery heatwave warms Pacific Ocean to new record

The waters of the North Pacific have seen their warmest summer on record, according to BBC analysis of a mysterious marine heatwave that is perplexing climate scientists.

Sea surface temperatures from July to September exceeded 0.25C above the previous record set in 2022, covering an area nearly ten times the size of the Mediterranean Sea.

Climate change is known to increase the likelihood of marine heatwaves, but experts are struggling to understand why the North Pacific has remained so hot for such an extended period. Some researchers suggest that the extra heat may lead to a colder winter start for the UK.

There's definitely something unusual going on in the North Pacific, stated Zeke Hausfather, a climate scientist at Berkeley Earth. The significant temperature rise across this large region is quite remarkable.

The BBC analyzed data from the European Copernicus climate service to assess average temperatures in the North Pacific during the summer months. As the data reveals, the region has been warming quickly, and 2025 shows significantly higher temperatures than previous years.

It is no surprise that ocean temperatures are rising; global warming has already tripled the number of extreme heat days in oceans worldwide. However, the observed temperatures have exceeded predictions from climate models that factor in human carbon emissions.

Analysis implies that sea temperatures observed in the North Pacific during August had less than a 1% chance of occurring in any given year due to various natural weather variabilities, such as weaker-than-normal winds that tend to retain more heat in surface waters.

Another intriguing aspect might be the recent changes in shipping fuels, which has been linked to warming in the region. Before 2020, dirty fuel used in shipping released large amounts of sulphur dioxide, which, while harmful, helped reflect sunlight and cooled ocean temperatures. The elimination of this cooling effect may mean humans are now seeing the full extent of global warming.

The marine heatwave has already influenced weather conditions across the Pacific, creating extreme summer temperatures in Japan and South Korea, as well as intensified storm activity in the US. According to Amanda Maycock, a climate dynamics professor, warm Pacific waters contribute to moisture and heat that facilitates severe weather patterns.

The long-term impacts of this warming trend may also extend to the UK and Europe. The relationship between weather patterns worldwide, known as teleconnections, suggests that warm conditions in the North Pacific generate atmospheric changes that could lead to colder weather in Europe as atmospheric waves shift the typical weather patterns.

Additionally, a developing La Niña phenomenon in the eastern tropical Pacific could also affect temperatures in the UK. La Niña is associated with cooler surface waters in that region and typically increases the chances of colder winters in the UK, although the situation is complex and not entirely predictable.

Overall, this extraordinary heat in the North Pacific raises significant questions about the implications for global weather patterns, underscoring the need for further research and understanding.