A weather phenomenon that involves unusually cold ocean temperatures in the equatorial Pacific Ocean. La Nina events don't occur as often as El Nino events
New Mexico Office of the State Engineer and Interstate Stream Commission, Water Use & Conservation, Glossary of terms provided by the National Drought Mitigation Center, New Mexico, USA 2015. http://www.nmdrought.state.nm.us/contacts.html, (ND/ Drought Mitg - Amer) {893}