The El Nino climate phenomenon, known for its significant impact on global weather patterns, is expected to reemerge later this year, raising concerns about further increases in worldwide temperatures. Experts estimate there is a 50 to 60 percent probability that El Nino conditions will develop between July and September, possibly extending into the following months. This forecast comes from the United States National Oceanic and Atmospheric Administration (NOAA), which closely monitors oceanic and atmospheric changes. Meanwhile, the World Meteorological Organization is set to release a detailed update on El Nino’s status this Tuesday, providing fresh insights into what lies ahead.
To understand the significance of El Nino, it is important to recognize its place within the broader El Nino-Southern Oscillation (ENSO) climate cycle, which also includes its cooler counterpart, La Nina. These two phases represent natural fluctuations in ocean temperatures and atmospheric conditions across the tropical Pacific Ocean. The term “El Nino,” meaning “the boy” or “the Christ Child” in Spanish, was originally coined by fishermen along the coasts of Peru and Ecuador in the 19th century. They used the name to describe an unusual warm ocean current that appeared around Christmas time, which adversely affected their fish catches. In contrast, scientists named the cooler phase “La Nina,” meaning “the girl,” to signify the opposite effect. Between these two extremes lies a neutral phase, where neither El Nino nor La Nina dominates.
El Nino events occur irregularly, typically every two to seven years, and are characterized by a weakening of the trade winds that usually blow from east to west across the tropical Pacific. This weakening allows warm water to shift eastward, raising sea surface temperatures in the central and eastern Pacific regions. Such changes disrupt typical weather patterns, influencing rainfall and wind currents not only locally but across the globe. The additional heat released from the ocean surface into the atmosphere during El Nino episodes often leads to a temporary spike in global temperatures. This phenomenon explains why years marked by El Nino tend to rank among the warmest on record. Meteorologists estimate that a typical El Nino event can raise the global average temperature by approximately 0.1 to 0.2 degrees Celsius.
The climatic effects of El Nino are far-reaching. Regions such as Southeast Asia, Australia, southern Africa, and northern Brazil often experience drier conditions during an El Nino phase. Conversely, areas including the Horn of Africa, the southern United States, Peru, and Ecuador usually see increased rainfall. These shifts can have profound impacts on agriculture, water resources, and ecosystems, sometimes triggering droughts or floods depending on the location.
The most recent El Nino event took place during 2023 and 2024, contributing significantly to 2023 becoming the second warmest year on record and 2024 setting a new global temperature high. Climate experts, including Carlo Buontempo, director of the European Union’s Copernicus Climate Change Service, have warned that if El Nino reappears this year, 2026 could potentially break existing temperature records. However, the full impact of El Nino on global temperatures often lags behind its initial development. climate scientist Tido Semmler from Ireland’s National Meteorological Service, if El Nino emerges in the latter half of 2025, the most intense warming effects might be felt in 2027 rather than 2026. He also emphasized that even without El Nino, the ongoing trend of global warming alone could make 2026 the warmest year recorded so far.
On the other side of the ENSO spectrum, La Nina events cool the eastern Pacific Ocean and generally last between one and three years. The latest La Nina episode, which began in December 2024, was relatively mild and short-lived, expected to transition into a neutral phase by the February to April period. La Nina typically brings wetter weather to parts of Australia, Southeast Asia, India, Southeast Africa, and northern Brazil, while causing drier conditions in certain regions of South America. Despite the cooling influence of La Nina, 2025 still ranked as the third hottest year on record, underscoring the powerful influence of long-term climate change.
In a bid to improve the accuracy of monitoring these climate phenomena, NOAA introduced a new method in February for identifying El Nino and La Nina events. The previous system, known as the Oceanic Nino Index (ONI), compared three-month average sea surface temperatures in a specific Pacific region against a 30-year historical average. However, with the oceans warming rapidly due to climate change, this baseline has become less reliable. The new approach, called the Relative Oceanic Nino Index (RONI), measures how warm or cool the east-central Pacific is relative to the rest of the tropical Pacific. NOAA describes RONI as a clearer and more dependable tool for tracking ENSO events in real time, allowing scientists and policymakers to better anticipate and respond to the global impacts of these natural climate cycles.
