The monsoon accounts for over 70 per cent of India's annual rainfall.
Cyclone Remal, which formed in the Bay of Bengal, has led to India witnessing a rare phenomenon with the monsoon setting in simultaneously over Kerala and most parts of the northeast. The last time this happened was in 2017 and there was one factor in common - Cyclone Mora had formed just before the monsoon that year, also over the Bay of Bengal.
The India Meteorological Department said on Thursday that the Southwest Monsoon has set in over Kerala and also advanced into most of northeast India, including all of Nagaland, Manipur, Mizoram and Arunachal Pradesh, and most parts of Tripura, Meghalaya and Assam.
The monsoon usually arrives in Kerala on June 1 and in the northeast on June 5.
The IMD had said on Wednesday that conditions were rapidly becoming favourable for the onset of the southwest monsoon over Kerala within the next 24 hours. It has set in on May 30, a day earlier than the weather bureau's first forecast.
Speaking to NDTV, IMD Director General M Mohapatra said, "As of today, the southwest monsoon has reached Kerala and covered most parts of the state. It has also covered some parts of Tamil Nadu and also most parts of the northeastern states."
The IMD has predicted above-normal monsoon this year. The weather office defines average or normal rainfall as between 96 and 104% of a 50-year average of 87 cm for the June-September monsoon season.
The monsoon accounts for over 70 per cent of India's annual rainfall and plays a major role in the Indian economy as it is the only source of irrigation for nearly 50 per cent of the country's farmland. Large swathes of the country also depend on it for the drinking water supply.
Delhi and other parts of the north, which are still reeling under record-high temperatures, will have to wait for the rain to reach them. The rains are expected to reach the national capital by the end of June.
On the heatwave, the IMD chief said, "The monsoon has set in over Kerala two days early and it will reach Mumbai on June 8. If we look at the weather pattern, the monsoonal features, I will say it is in very good condition for the continuance of this spell."