Monthly El Niño Southern Oscillation Index, 1986–2016
New Zealand's Environment Reporting Series: The Ministry for the Environment and Statistics New Zealand
The El Niño Southern Oscillation (ENSO) is the movement of warm equatorial water across the Pacific Ocean and the atmospheric response. It occurs every 2–7 years, typically lasting 6–18 months. ENSO has three phases: neutral, El Niño and La Niña. In New Zealand an El Niño phase in summer can bring increased westerly winds, more rain in the west, and drought in the east; in winter it can lead to more cool southerly winds. During a La Niña phase we may experience more north-easterly winds, wetter conditions in the north and east, and higher sea levels. This dataset relates to monthly ENSO values. More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.
National Oceanic and Atmospheric Administration; NIWA