Context: The article discusses the onset of an El Niño event, a complex weather phenomenon that affects global climate patterns, causing extreme weather conditions and temperature fluctuations. El Niño events occur when there is an abnormal warming of the ocean waters in the eastern Pacific, near the equator, and have significant impacts on global weather patterns. The article reports on the official declaration of the start of an El Niño event by US scientists, who warn of potential extreme weather and higher temperatures.