The overall rainfall across the country as a whole this monsoon almost matched the early predictions of 96 per cent rainfall, but 17 per cent of the country saw large deficiencies of more than 20 per cent.
These areas were Uttar Pradesh, Delhi, Punjab and parts of Madhya Pradesh and Maharashtra.
The season-ending report by the India Meteorological Department shows that Uttar Pradesh received about 30 per cent less rainfall than its normal, while Delhi had a 26 per cent shortfall.
Punjab (-22 per cent), eastern Madhya Pradesh (-24 per cent) and Vidarbha (-23 per cent) also received very less rain.
On the other hand, about 18 per cent of the country — Tamil Nadu, western Rajasthan and Gujarat — received excess rainfall.
The remaining 65 per cent of the country, including the southern peninsula and central India, received normal rainfall, even though Kerala and interior Karnataka had not received their actual quota of rain until the third week of August.
“The rainfall this year has been peculiar in its distribution. Most systems originated in the Bay of Bengal while the Arabian Sea remained largely inactive this season. Thus, monsoon winds mostly skirted the west coast, thereby bringing lesser rainfall in Kerala, coastal Karnataka,” A K Srivastava, head of climate monitoring and analysis group at IMD, Pune, said.
Though the southwest monsoon set in on a promising note, arriving on May 30 over Kerala, its momentum did not continue during the second-half of the season. While June and July had surplus rainfall of 4 per cent and 2 per cent, respectively, August and September remained deficient by 13 per cent and 12 per cent, respectively.
This year, there were only 39 days when low-pressure systems, the atmospheric phenomenon which propels rainfall activity over a region, prevailed. Normally, there are about 58 days when such systems are experienced in the entire season.
Extremely heavy rainfall events were repeatedly experienced. Rainfall in excess of 210 mm within 24 hours left areas under water and flashfloods displaced thousands of people. Besides Mumbai, Bengaluru, Hyderabad, Guwahati and Chandigarh, areas in north-east, Bihar, West Bengal, Odisha, Rajasthan, Jharkhand and parts of Uttar Pradesh saw flooding at different times in the season.