The India Meteorological Department (IMD) has forecast that the Southwest Monsoon is likely to set in over Kerala on May 26, 2026, nearly a week ahead of its normal onset date of June 1. The forecast carries a model error margin of plus-minus 4 days.
According to a press release issued by the Ministry of Earth Sciences, the onset of the Southwest Monsoon over Kerala marks the beginning of the Monsoon season across the Indian mainland and signals relief from the intense summer heat.
The IMD stated that it has been issuing operational forecasts for the monsoon onset over Kerala since 2005 using an indigenously developed state-of-the-art statistical model. The model takes into account six major meteorological predictors, including minimum temperatures over northwest India, pre-monsoon rainfall activity over the southern peninsula, outgoing longwave radiation patterns, and lower tropospheric wind conditions over the Indian Ocean and Pacific regions.
The weather office noted that its forecasts during the past 21 years were accurate except in 2015. In recent years, the actual onset dates have varied between May 24 and June 8. In 2025, the monsoon reached Kerala on May 24 against the forecast date of May 27.
An early onset of the southwest monsoon is generally seen as favourable for agriculture and water availability in many parts of the country.