"I am sad to know about the heavy rains leading to floods in certain areas of the state, which have caused loss of lives, injuries and damage to property," Mukherjee, in individual messages sent to the Governors of Assam, Bihar and Madhya Pradesh, said.
"Please convey my heartfelt condolences to the families of the deceased and prayers for the speedy recovery of the injured persons. Kindly keep me informed of progress in addressing the situation," the President said.
"My thoughts are with all those affected by this natural calamity. I understand rescue and relief operations are currently underway.
According to Assam State Disaster Management Authority, two persons were killed at Bokakhat in Golaghat district taking the toll to 31.
Nearly 17 lakh people have been affected in 2,266 villages in 21 districts in the state, with Morigaon being the worst-hit.
The flood situation remained grim in 12 districts of Bihar where an estimated 27.50 lakh people were affected though no fresh casualty was reported today, with the toll standing at 26.