More than 50 people died after being struck by lightning in the month of July, including over 30 in the northern state of Uttar Pradesh.
A government official says lightning has killed at least 20 people with thunderstorms and heavy rains lashing eastern India.
Disaster Management official Amod Kumar Sharan said the deaths occurred on Tuesday. He raised the overall death toll in Bihar state to more than 100 from lightning and flooding since the monsoon season started in June.
Last Sunday, 33 people were killed by lightning in the northern state of Uttar Pradesh. They were mostly farmers working in the field.
Millions of people have been hit by floods, their homes and crops devastated by surging waters in the worst-hit Bihar and Assam states.
South Asia's monsoon rains, which hit the region from June to September, are crucial for the rain-fed crops planted during the season.