The India Meteorological Department (IMD) on Friday said that monsoon will hit Kerala coast on May 26, which is six days earlier than its normal schedule day of June 1 in the mainland. IMD also said that the southwest monsoon is very likely to advance into South Andaman Sea, some parts of Southeast Bay of Bengal and Nicobar Islands on May 16, against normal May 20.

“This year, the south west monsoon is likely to set in over Kerala on May 24, with a model error of ± 4 days,” IMD said in a statement. This year’s monsoon is keenly awaited amid forecast by IMD of a below-normal rainfall during June-September season amid prediction of a super El Nino.

The weather bureau also said that its “operational forecasts” (inclusive of error margin) of the date of monsoon onset over Kerala during the past 21 years (2005-2025) were proved to be correct, except in 2015.

“Advance of the monsoon over Indian main land is marked by monsoon onset over Kerala and is an important indicator characterizing the transition from hot and dry season to a rainy season,” IMD said.

As the monsoon progresses northward, relief from scorching summer temperatures is experienced over the areas. IMD has been issuing operational forecasts for the date of monsoon onset over Kerala from 2005 onwards, based on a statistical model.

The six predictors used in the models are — 1) Minimum Temperatures over north-west India, 2) Pre-monsoon rainfall peak over south Peninsula, 3) Outgoing long wave radiation (OLR) over south China Sea, 4) Lower tropospheric zonal wind over equatorial south-east Indian Ocean, 5) Outgoing OLR over south-west Pacific Ocean and 6) Upper tropospheric zonal wind over equatorial north-east Indian Ocean, IMD said.

Monsoon onset over Kerala

Year Actual Forecast

2019 June 8 June 6

2020 June 1 June 5

2021 June 3 May 31

2022 May 29 May 27

2023 June 8 June 4

2024 May 30 May 31

2025 May 24 May 27

Published on May 15, 2026