The India Meteorological Department (IMD) has said the current monsoon has been the heaviest since 1994, classifying it "above normal", and this year's season has been longer than usual.
The death toll in eastern India from torrential late monsoon rains has risen to nearly 140, officials said Tuesday as hospitals and schools were inundated with dirty rainwater.
Over the past four days 111 people have died in Uttar Pradesh state and another 28 lost their lives in neighbouring Bihar, government officials told AFP.
Some 900 inmates had to be shifted from a Ballia district prison in Uttar Pradesh to "ensure their safety and health" after rainwater flooded the premises.
Residents of Patna -the capital of Bihar, home to two million people - used lifeboats to escape heavily water-logged homes.
Although the rains have stopped, large swathes of the city remained submerged, with schools and shops shut.
Images showed rainwater swamping hospital wards and residential areas where disaster management officials delivered milk, bananas and drinking water pouches on inflatable boats.
The annual monsoon season usually lasts from June to September but late heavy rains have continued to lash several parts of the country this year, wreaking havoc.
"In spite of late monsoon onset and large deficient rainfall during the month of June, the seasonal rainfall ended in above normal category," the IMD said on Monday.