India's June-September monsoon ended with 13% below-normal rainfall, making it the driest since 2015. The rainfall was also the fourth-lowest since 2001. June, August and September recorded deficits of over 35%, 16.3% and 7.6%, respectively, while July saw a 1% surplus. This is due to an abnormal warming of surface waters in Pacific Ocean, a phenomenon known as El Niño.