ENSO Impacts

This section contains tools that help explore the historical relationship between ENSO and regional climate.

ENSO events (in particular to the strong El Niño events of 1982–83 and 1997–98) have been connected to impacts on almost every aspect of human life: disease outbreaks, low and high agricultural yields, natural disasters, availability of water resources, energy demand, disruption to hydropower generation, price fluctuations, fishery catch fluctuations, animal movements, forest fires, the economic well-being of nations, and many others.

Overall, however, ENSO impacts are only a subset of the impacts of year-to-year climate variability. At most ENSO may be responsible for about 50% of seasonal climate variability in some regions, but in most regions of the world its influence is much smaller.

    This figure shows the historical probability (given as a percentage) of seasonal (Jan-Mar, Apr-Jun, Jul-Sep, Oct-Dec) station precipitation totals falling within the upper (wet) one-third, middle (near-normal) one-third, or bottom (dry) one-third of the historical (1901-1990) distribution given the state of ENSO (El Niño, Neutral, La Niña) during that same season.
    These maps display the frequency with which 3-month seasonal precipitation totals were observed to be within the upper (wet) one-third, middle (normal) one-third, or bottom (dry) one-third (Tercile) of the historical (1950-2002) distribution given the state of ENSO (El Niño (nino), La Niña (nina)) during that same season.
    This plot shows the relationship between summer monsoonal rainfall in India and ENSO.