El Niño causes poor monsoons 7 out of 10 years

About 70% of El Niño events since 1980 have been associated with poor summer monsoons, suggesting that the link between Pacific conditions and the country’s June-September rainfall is one of the strongest among global weather phenomena affecting India’s monsoon. The link is significant given the latest forecasts from U.S. and European weather agencies, which predict El Niño will occur within two to three months and say it is expected to be stronger than previous forecasts. In the monsoon outlook, In-mold development department Rainfall is expected to be below normal this season.

TOI analyzed all El Niño events (defined by US agency NCEP) since 1980 and the corresponding monsoon performance. Among these 13 years, there were 7 years with insufficient or severely insufficient monsoon (below 90% of the long-term average), 2 years with below normal (90-96%), 3 years with normal monsoon, and 1 year with excessive monsoon. Of the two below-normal years, 2018 was nearly deficient (below 91%). According to the IMD (which uses different indicators to define El Niño years), there are eight such years, six of which lacked the monsoon, including one (2002) where the monsoon was severely lacking (rainfall was less than 80% of the LPA). In addition, there are years like 2014 when Pacific warming affects the monsoon, but El Niño ultimately does not develop. During El Niño, surface waters in the eastern and central tropical Pacific warm abnormally, causing changes in wind patterns that affect global weather in different ways. Despite the presence of El Niño, there are notable exceptions when the monsoons are normal. The most commonly cited example is in 1997, when one of the strongest El Niño events on record occurred, but rainfall in India remained normal from June to September. That year, conditions indian ocean – a phenomenon known as the Indian Ocean Dipole – strongly favors rainfall over India and is thought to counteract the effects of El Niño. Global agencies have reached consensus on the likelihood of an El Niño forming this summer. European agency ECMWF predicts that there is a good chance that this situation will develop between May and June and intensify further towards the end of the year into a very strong event, dubbed by some as a “Super El Niño”.