What Is El Niño, and What Does It Mean for Weather, Water, and the Global Economy? El Niño is a complex weather phenomenon that affects global climate patterns.
This year's event has exceeded all previous records in terms of speed and intensity, prompting alarm bells from meteorological agencies and researchers.
The Science Behind El Niño El Niño occurs when warmer than normal sea surface temperatures in the equatorial Pacific trigger a chain reaction that affects rainfall, temperatures, and hurricane activity worldwide.