New Delhi | The southwest monsoon set over Kerala on Thursday, according to the India Meteorological Department (IMD).

Typically, the monsoon arrives in Kerala around June 1, which marks the beginning of the Southwest monsoon season (June-September).

"The southwest monsoon has further advanced into the remaining parts of southwest and southeast Arabian Sea, some parts of west central and east central Arabian Sea, entire Lakshadweep islands, Kerala and Mahe, some parts of Karnataka and Tamil Nadu, remaining parts of Comorin area, southeast Bay of Bengal and some more parts of southwest, west central, east central and northeast Bay of Bengal today the 4th June, 2026," the IMD said. Previously, the weather department had predicted that the monsoon would begin over Kerala on May 26; however, the arrival was delayed.

Last week, the department revised its forecast for seasonal rainfall, indicating that it would be below normal.

The IMD expects rainfall in India to be around 90% of the long-period average (LPA) this year.

The LPA refers to the rainfall recorded in a specific region over a defined period, such as a month or season, averaged over a long duration, typically 30 to 50 years.

The long-period average (LPA) of seasonal rainfall over the country as a whole, based on data from 1971 to 2020, is 87 cm. If the monsoon season sees less than 90 pc of LPA rainfall, the IMD classifies it as 'deficient'.

One reason behind the below-normal rainfall could be the emergence of El Nino conditions, which lead to less rain during the monsoon in the country.

Currently, neutral El Nino-Southern Oscillation conditions are transitioning towards El Nino conditions over the equatorial Pacific region.

The IMD said that El Nino conditions are likely to be weak in June, and moderate to strong in September.