El Niño, a natural climate phenomenon that occurs every two to seven years, is currently drawing close attention as it may be the strongest event in 40 years, according to the World Meteorological Organization (WMO). This phenomenon involves periodic warming of ocean surface temperatures in the central and eastern Pacific, which can have wide-reaching effects on global weather patterns. To track its development, scientists at the Mercator Ocean research institute in Toulouse are using a digital twin of the ocean. This is a 3D model that simulates real-time ocean conditions, helping to predict how El Niño will evolve and what effects it may have in the coming months. According to the WMO, the current El Niño could be the strongest since records began 40 years ago. Sea surface temperatures in the Niño 3.4 region of the Pacific—key for measuring El Niño—have already reached anomalies of about +2 °C compared to the historical average, with some areas showing anomalies as high as +4 °C. These temperature spikes indicate a particularly strong El Niño for September, and the phenomenon is expected to peak in intensity during November and December. Historically, El Niño has been linked to extreme weather events. It has caused or worsened droughts and increased fire risks in regions like the Amazon, Central America, Indonesia, and Australia. In India, it has disrupted monsoon patterns, while in eastern Africa, it has led to heavy rainfall. However, the specific impacts vary by region and are not solely determined by the strength of El Niño, as noted by the WMO. Other factors, such as local geography and existing climate conditions, also play a role. Scientists are also observing a large amount of heat stored in the deep ocean, which is crucial for understanding how much heat may resurface and influence weather patterns. This information helps forecasters, including those at Météo-France, make more accurate seasonal predictions. The WMO predicts that from September to November 2026, most land areas will experience higher-than-normal temperatures, with precipitation patterns consistent with a strong El Niño in the Pacific. This natural phenomenon is compounding the effects of human-caused climate change, contributing to the unusually high temperatures seen today. The year 2024 was the warmest on record, following the previous El Niño, as heat stored in the ocean was released into the atmosphere the following year.