United Nations, Dhu-AlQa'dah 17, 1436, Sep 1, 2015, SPA -- The current El Nino weather phenomenon is expected to strengthen before the end of the year and to peak between October and January, the World Meteorological Organization (WMO) said Tuesday. Climate models and experts suggest surface waters in the east-central Pacific Ocean are likely to be well above normal temperatures, potentially making this year's El Nino one of the strongest since 1950, following similar weather events in 1972, 1982, and 1997, the U.N. weather agency said. Both El Nino and the similar La Nina weather patterns cause global changes in temperatures and rainfall. Developing countries dependent upon agriculture and fishing, particularly those bordering the Pacific Ocean, are the most affected. A recent study reported a strong tendency to more frequent extreme El Ninos. --SPA 18:48 LOCAL TIME 15:48 GMT www.spa.gov.sa/w