According to Reuters, the World Meteorological Organization predicted on August 31 that La Nina will last at least until the end of this year. At present, La Nina phenomenon began around September 2020. This prediction means that a rare "triple" La Nina climate event will occur in the northern hemisphere. La Nina and El Nino usually occur once every two to seven years, with neutral years in between. El Nino is a climate phenomenon caused by the abnormal rise of sea water temperature in the Middle East of the Pacific equator. La Nina, on the contrary, refers to the sea surface temperature in this region of the Pacific Ocean being lower than the normal temperature for a period of time. Meteorologists say that two consecutive La Nina winters are common in the northern hemisphere, but three consecutive winters are rare. Since 1950, the three-year "triple" La Nina phenomenon has occurred only twice. (news agency)