New Delhi | The southwest monsoon is expected to set in early over Kerala on May 26, the India Meteorological Department (IMD) said in its forecast on Friday.

The monsoon, the primary rain-bearing system, normally arrives in Kerala around June 1 and advances northwards to cover other parts of the country.

The onset of monsoon in the state marks the beginning of the southwest monsoon season (June to September). Last year, the onset of the monsoon happened on May 24.

"This year, the southwest monsoon is likely to set in over Kerala on May 26 with a model error of ± 4 days (could occur four days before or after)," the IMD said.

The weather office also added that conditions were favourable for the monsoon to advance over parts of the South Bay of Bengal, Andaman Sea, and Andaman and Nicobar Islands during the next 24 hours.

"The advance of the southwest monsoon over the Indian mainland is marked by monsoon onset over Kerala and is an important indicator characterising the transition from the hot and dry season to the rainy season," the IMD said.

"As the monsoon progresses northward, relief from scorching summer temperatures is experienced over the areas," it added.

The four-month monsoon season brings almost 70 per cent of the country's annual rainfall. It is critical for agriculture and crops, for the economy as a whole, and to recharge reservoirs and aquifers.

The IMD has said that India might receive below-normal rainfall this year during the monsoon season.

The country is likely to get 80 cm of rainfall in the monsoon months, with the long-period average (1971-2020) of seasonal rainfall at 87 cm.

The IMD said this could be due to the emergence of the El Nino conditions, which cause less rainfall in the country.

In its monthly forecast on May 1, the department said that El Nino-Southern Oscillation (ENSO)-neutral conditions over the equatorial Pacific were evolving toward El Nino conditions