More than three million Hindu devotees bathed in the Ganges river on Tuesday to mark one of the most auspicious days of the two-month-long festival.
Millions are expected to repeat the ritual on Wednesday.
India reported 184,372 new cases on Tuesday - its highest-daily spike yet.
Many have criticised the government for allowing the festival to go ahead amid a raging pandemic.
Officials said that nearly 900,000 people had taken a dip in the holy river by afternoon on Wednesday, which is considered to be the most auspicious day of the entire festival.
Hindus believe that the Ganges river is holy, and taking a dip in the water will cleanse them of their sins and bring salvation.