The incident took place at Kesla village under Lailunga police station limits late Friday evening, a police official said.
The deceased were identified as Khulaso Sarthi (60), her daughter Kamla (30) and Sukhiram Banjara (34), all residents of Lailunga, he said.
"The victims were hit by lightning when they were trying to find shelter from rain," he said, adding that before the incident, they had gone to a nearby temple.
On being informed, police rushed to the village and sent their bodies to the Community Health Centre in Lailunga for autopsy, the official said.
Comment: Hundreds of thousands evacuated as Typhoon Noru makes landfall in Vietnam's Da Nang