Bengaluru receives rainfall the earliest as per the Advancing Monsoon in India, generally marked by early onset of monsoon in southern India
The southwest monsoon generally advances from the south to the north.
It first hits the Kerala coast around June 1st, which is considered the official onset of the monsoon in India.
Bengaluru, being in southern Karnataka, receives monsoon rains soon after the onset in Kerala, usually in the first week of June.
So while Bengaluru does get early monsoon rains, Kerala is the earliest recipient.