New Delhi: The onset of southwest monsoon over Kerala this year is likely to be delayed by four days, the India Meteorological Department (IMD) said on Friday. The monsoon is expected to hit the southern state by June 5, four days after its normal onset date.

"This year, the onset of southwest monsoon over Kerala is likely to be slightly delayed as compared to the normal date of onset. The monsoon onset over Kerala this year is likely to be on 5th June with a model error of plus or minus 4 days," the IMD said.

The onset of monsoon over Kerala marks the official commencement of the four-month rainfall season in the country.

The IMD said in the Indian monsoon region, initial monsoon rains are experienced over south Andaman Sea and the monsoon winds then advance north-westwards across the Bay of Bengal. As per the new normal dates of monsoon onset/progress, the southwest monsoon advances over the Andaman Sea around May 22.