It said quantitatively, the seasonal rainfall during June 1 to September 30, 2020 was 95.8 cm against the long period average of 88.0 cm based on data of 1961-2010 (109% of its Long Period Average). “Thus 2019 and 2020 are the two consecutive years with above normal monsoon rainfall, after 1958 (110% of LPA) and 1959 (114% of LPA ),” it stated.
As on October 1, southwest monsoon has withdrawn from Punjab, western Himalayan region, Haryana, Chandigarh, Delhi and many parts for Rajasthan and some parts of Uttar Pradesh. The withdrawal line of the Southwest Monsoon passes through Latitude 29°N/ Longitude 81°E, Lakhimpur Kheri, Shahjahanpur, Alwar, Nagaur and Latitude 26°N/ Longitude 70°E.
Also read: The country so far received 7 per cent excess rainfall – Met Department
Considering four broad homogenous regions of India, the monsoon seasonal rainfall during 2020 was 106%, 84%, 115% & 129% of LPA respectively over East and North-East(NE), North- West(NW), Central and South India. This meant seasonal rainfall has been excess over Central and South India, normal over East and NE India and deficient over NW India.
Out of 36 meteorological subdivisions, 2 subdivisions received large excess, 13 received excess and 16 subdivisions received normal monsoon rainfall during 2020 while only 5 subdivisions received deficient rainfall (see the map). These 5 Met subdivisions which got deficient rains were Nagaland, Manipur, Mizoram & Tripura (- 32%), West Uttar Pradesh (-37%), Uttarakhand (-20%), Himachal Pradesh, (- 26%), Jammu & Kashmir and Ladakh (-34%) .
Considering month to month rainfall variation over India as a whole, the season is very uniquely placed in the historical record for its distinct and contrasting month to month variation. The rainfall over country as a whole was 118%, 90%, 127% and 104% of LPA during June, July, August and September respectively.
Monsoon in 2020 withdrew from western parts of northwest India on September 28, 2020 against the normal date of September 17, 2020 with a delay of around 11-days. Withdrawal was delayed mainly due to active monsoon trough in association with the formation of 2 low pressure systems in Sept 2020.
– globalbihari bureau
