The deceased include Koothattukulam native Nikhil, 27, and a girl whose identity is yet to be found.
Lakhimpur is the worst-hit district with more than 1.3 lakh people suffering, followed by Majuli with nearly 65,000 persons and Darrang with over 41,300 people being affected.
Saturday's flooding in rural areas took out roads, cellphone towers and telephone lines, leaving families uncertain about whether their loved ones survived the unprecedented deluge.
The India Meteorological Department (IMD) said Delhi recorded 139 mm of rainfall, the highest one-day rain for August in at least 13 years.
Several districts in south Bengal including Hooghly, Purba Medinipur, Howrah, South 24 Parganas -- have been reeling under flood woes following heavy rain and discharge of water from Damodar Valley Corporation (DVC) dams.
The rainfall is likely to taper off by Tuesday. Though a fresh low-pressure area is expected to form over the Bay of Bengal around July 28, Kerala is likely to see only below normal rainfall then.
The shocking incident took place in the small Talai village near Mahad town in the hilly stretch of Maharashtra's Raigad district.
At least 25 people were killed and a total of 1.24 million people were affected by the massive floods.
Days of heavy rain turned normally minor rivers and streets into raging torrents this week and caused the disastrous flooding that swept away cars, engulfed homes and trapped residents.
The Kerala chief minister remembered the 'invaluable' support of European counties when the State was ravaged by floods in 2018 and 2019