El Niño is the unusual warming of the surface waters of large parts of the tropical Pacific Ocean. Occurring around Christmastime, it is named after the Christ child. El Niño occurs erratically every three to seven years. It brings heavy rains and flooding to Peru, Ecuador, and Southern California, and a milder winter with less snow to the northeastern United States. Studies reveal that El Niño is not an isolated occurrence, but is instead part of a pattern of change in the global circulation of the oceans and atmosphere. The 1982–1983 El Niño was one of the most severe climate events of the twentieth century in both its geographical extent as well as in the degree of warming (14°F or 8°C).