Monsoon season began in Mumbai on June 9. The south west monsoon arrived in the city two days ahead of the normal schedule. Rains arrived early due to favourable conditions along the Maharashtra coast, an India Meteorological Department (IMD) official told PTI. Usually, rains hit Mumbai by June 11. However, last year, rains made its onset on June 24 due to 'Biparjoy' cyclone over the Arabian Sea, an India Meteorological Department (IMD) official told PTI. Watch the video to know more.