The ongoing El Niño phenomenon has reached unprecedented levels, weeks before it is anticipated to peak, according to climate scientists who closely monitor Pacific Ocean temperatures. On September 19, sea surface temperatures in a crucial area of the central-eastern Pacific soared to 3.05°C above average, surpassing the previous record of 3.02°C set during the significant El Niño event of 2015. While some longer-term indicators of El Niño have yet to reach record-breaking status, experts believe this is likely to change as the year progresses.
Understanding El Niño and Its Measurement
El Niño is a naturally occurring climate pattern that emerges every two to seven years, typically lasting around a year. It involves a weakening or reversal of trade winds that usually blow from east to west across the Pacific Ocean, allowing warm water to spread eastward. This process releases heat from the ocean into the atmosphere, potentially increasing global temperatures and altering weather patterns worldwide.
To declare an El Niño event, forecasters observe temperatures in a key region of the Pacific Ocean, with an El Niño being confirmed when these temperatures remain consistently 0.5°C above normal. The strength of El Niño can be assessed using various methods, including the Oceanic Niño Index (ONI), which compares daily sea surface temperatures to historical averages.
Current El Niño’s Global Impact
While every El Niño event differs, the current one is already influencing global weather patterns. However, its extraordinary strength does not guarantee equally extraordinary impacts. For instance, El Niño typically increases the likelihood of storms and floods in some regions and droughts and wildfires in others. In India, this year’s southwest monsoon has brought 15% less rain than usual, a common effect of El Niño years.
Additionally, El Niño often reduces hurricane activity in the Atlantic due to altered wind patterns in the upper atmosphere. In 2026, there have been no Atlantic hurricanes, marking the latest onset of hurricane activity since satellite monitoring began. Other anticipated effects include a heightened risk of coastal flooding in Ecuador, Peru, and the southern United States, alongside an increased threat of drought and wildfires in Brazil, Australia, and Indonesia. These weather changes can significantly impact agriculture, food security, and global economies.
Potential Effects on UK Weather
Although the UK is geographically distant from the tropical Pacific, El Niño can still influence its weather patterns, albeit less predictably than in other regions. The phenomenon is associated with a higher probability of wet and stormy conditions across north-west Europe during late autumn and early winter.
The Met Office has indicated that there are already signs pointing to increased rainfall and storm activity in the UK this autumn, particularly in November and December. The winter of 2015-2016, which coincided with a strong El Niño, saw a series of severe storms resulting in extreme flooding. While El Niño can also be linked to cold spells in late winter, this correlation is weak, with past evidence providing mixed results.
