India witnessed 125 extremely heavy rainfalls in September, October '21: IMDtext_fields
India Meteorological Department on Tuesday said that India recorded 125 extremely heavy rainfalls during September and October of 2021, the highest in five years. The rainfalls were spurred by the late withdrawal of the southwest monsoon and higher than normal low-pressure systems.
This year, 89 heavy rainfall events were recorded in September against 61 last year. It was 59 in 2019, 44 in 2018 and 29 in 2017.
In October, 36 such events were witnessed. It was 10 in 2020, 16 in 2019, 17 in 2018 and 12 in 2017.
The department said that the causes of disastrous weather episodes include the late withdrawal of the monsoon, a higher than normal number of low-pressure systems during the period, and the interaction of active western disturbances with low-pressure systems in October. Nine low-pressure systems, including two cyclones, one deep depression and six lows, affected the country during the period.
In Uttarakhand, unprecedented rains on October 18 and 19 claimed 79 lives. This year it received 203.2 mm rainfall in October against the normal of 35.3 mm. The interaction of a low-pressure area and an intense western disturbance also caused riverine flooding in west Uttar Pradesh.
Extremely heavy rainfall is anything above 204.4mm. While rainfall below 15 mm is deemed light, that between 15 and 64.5mm is deemed moderate, between 64.5mm and 115.5 is heavy, and between 115.6 and 204.4 mm is considered very heavy.
The southwest monsoon, supposed to withdraw from the country around October 15, withdrew later this year around October 25. This is the seventh-most delayed retreat since 1975. From June to September, however, the country received normal rainfall of 87 cm. This is less than the Long Period Average of 88 cm from 1961-2010.
This is also the third consecutive year that the country has recorded rainfall in the normal/ above normal category. It was above normal in 2019 and 2020.