The developing El Niño climate phenomenon has become the strongest on record, with daily sea surface temperatures in a key region of the central-eastern Pacific reaching 3.05°C above average on 19 September, surpassing the previous record of 3.02°C set during the very strong El Niño of 2015. Scientists monitoring the Pacific warn that longer-term measures have not yet hit record levels but are likely to do so, with the peak not expected until later this year.
According to BBC News, the daily sea surface temperature reading in the Niño 3.4 region — a key indicator for El Niño — broke the record on 19 September. The previous high was recorded during the 2015 event. While some longer-term indices have not yet reached record strength, scientists expect that to change as the phenomenon continues to develop.
El Niño is a naturally occurring pattern that happens every two to seven years and typically lasts about a year. It involves a weakening or reversal of trade winds that blow from east to west across the Pacific, allowing warm water to spread eastward and release heat into the atmosphere. This can boost global temperatures and drive major shifts in weather patterns worldwide.
The UK Met Office has said many of the expected impacts are already being felt. In Indonesia, wildfires fuelled by El Niño are affecting around 12.5 million people, according to the country's health ministry. The Met Office previously described the event as set to be "strongest in living memory."
Peak strength is still weeks away, and forecasters are closely watching for further intensification and its consequences for global weather, including potential droughts, floods, and temperature extremes.
Analysis
Why This Matters
- The record strength of this El Niño means it could drive even more extreme weather globally — including droughts, floods, and heatwaves — affecting food security and displacing communities.
- The heat released from the Pacific into the atmosphere may push global temperatures to new highs, compounding the effects of human-caused climate change.
- Impacts are already being felt, as seen in Indonesia where wildfires are affecting 12.5 million people. The full consequences will unfold over the coming months.
Background
El Niño is a natural climate cycle centred on the tropical Pacific Ocean. During an El Niño event, the normal pattern of trade winds weakens or reverses, allowing warm surface water to shift eastward. This changes where heat and moisture are distributed in the atmosphere, disrupting weather patterns around the world. El Niño typically lasts about a year and occurs every two to seven years. The previous record-holder was the 2015–2016 event, which contributed to widespread droughts, coral bleaching, and record global temperatures.
Key Perspectives
Scientists monitoring the Pacific: They measure sea surface temperatures in the Niño 3.4 region to track El Niño strength. The daily reading of 3.05°C above average is the highest on record. They note that longer-term averages may soon break records too, as the event has not yet peaked.
Met Office (UK): The agency has stated that many expected impacts are already being observed. They previously described this El Niño as set to be "strongest in living memory."
Indonesian health ministry: The ministry reports that wildfires fuelled by El Niño are affecting around 12.5 million people across the country. This illustrates the direct human toll of the event.
What to Watch
- Whether longer-term indices (e.g., three-month average of Niño 3.4 temperatures) also break records in the coming weeks.
- The timing and strength of the peak, expected later in 2026, and whether it surpasses the 2015–2016 event.
- Global weather impacts, particularly the risk of drought in Southeast Asia and Australia, and flooding in parts of the Americas.