The India Meteorological Department on Wednesday said the onset of monsoon is likely to be delayed by a week and it is now expected to arrive only by June 8.
The normal onset date for monsoon over Kerala is June 1 which also marks the official commencement of the four-month-long rainfall season.
"It is very likely to shift northwards gradually leading to favourable conditions for the onset of Southwest Monsoon over Kerala around June 8," the IMD said in its monsoon bulletin.
On Tuesday, the IMD had said the arrival of monsoon could be on June 7.
On Saturday, private weather forecaster Skymet too revised its forecast from June 4 to June 7.
Last month, announcing the expected day of monsoon arrival over Kerala, the IMD had said it could happen on June 6, with an error margin of plus or minus four days.
The Met Department has given a forecast of a normal monsoon for the season.
Several parts of the country are reeling under severe heatwave with temperatures touching 50 degrees Celsius in some parts. The arrival of monsoon is likely to give some respite from the scorching heat.