Southwest monsoon missed its date with the Kerala coast on Thursday but a top weather scientist sought to play the incident down saying it was not a "sign of worry.' "True, the onset over Kerala has not happened,' Ajit Tyagi, Director General of the India Meteorological Department (IMD) said here. The IMD had earlier forecast that the southwest monsoon will hit the Kerala coast on May 29, four days ahead of its normal June 1 onset. Tyagi said Kerala had experienced a spell of rainfall but the IMD was waiting for the weather system to be more fully settled to declare the onset. "The onset of monsoon is an activity which is important as it signals the arrival of rains over a major landmass. But it has nothing to do with the quantum of rainfall during the season,' Tyagi said.