El Niño, anomalous seasonal ocean current along the coast of Peru, and part of a much larger atmospheric phenomenon called the ‘southern oscillation’, which can have a substantial impact on vineyard production in several countries where climate is affected by the Pacific Ocean. The phenomenon recurs every two to ten years, and is associated with atmospheric pressure changes in the South Pacific; it can be predicted well in advance.
Typical but severe effects were felt in 1998, which started with serious flooding in California and continued there throughout spring and early summer to retard the likely harvest dates. The Australian 1997–8 growing season on the other hand was generally affected by drought, decreasing quantity but sometimes increasing quality. There was a similar weather pattern in New Zealand. Chile’s wine regions experienced a generally cooler, wetter growing season with downy mildew in some areas for the first time. In Argentina around Mendoza, summer storms before vintage created bunch rot problems. Latest reports are that hopes are fading of a strong El Niño in 2014 to alleviate drought in California.
