This paper presents the impact of ENSO phase (El Niño and La Niña) on the variability of temperature and rainfall in Chiang Mai province, Upper Northern Thailand, and to identify the relation between ENSO index and temperature and rainfall. The study used data from four weather stations located at the altitude ranging from 320 to 1400 m a.s.l., covering the period of 1988 to 2011. We used two…