Many of the dead were farmers who were killed as they worked in their paddy fields.
Bangladesh is prone to electrical storms but this year they have been particularly severe.
Experts suggest a general rise in temperatures and deforestation may be factors.
Other victims included two students in the capital, Dhaka, who were struck as they played football, and a teenage boy who died when he went to collect mangoes.
About 90 people have been killed by lightning since March, compared to a total of 51 people in the whole of 2015, Voice of America (VoA) reported.
The head of Bangladesh’s disaster management body Mohammad Riaz Ahmed told VoA he was “indeed concerned” by the rise in the number of deaths.
He said further thunderstorms were predicted for later this month.
Strong tropical storms regularly hit Bangladesh ahead of and during the monsoon season, which runs from June to September.
