Monsoon to reach Kerala early on May 26: IMD

• Southwest monsoon is likely to hit Kerala on 26 May
• The onset is nearly a week ahead of the normal 1 June date
• El Niño may cause a weak monsoon season across the mainland

The southwest monsoon is likely to arrive in Kerala on May 26 this year, nearly a week before its normal onset date of June 1, according to the India Meteorological

Department (IMD). The weather agency said the forecast carries a possible error margin of plus or minus four days. The arrival of the monsoon over Kerala marks the official beginning of the rainy season across the Indian mainland and brings relief from the intense summer heat affecting several states. The monsoon is also expected to advance over the Andaman and Nicobar Islands around May 16. LIVE | SSLC Result 2026 Kerala Live Updates: How to Check Kerala Board SSLC 10th Result Marksheet Despite the possibility of an early onset, weather agencies, including IMD and Skymet, have indicated that the 2026 monsoon season may remain weak due to the impact of El Niño conditions.

How IMD Predicts Monsoon Arrival In Kerala

The IMD said it has been issuing operational forecasts for the Kerala monsoon onset since 2005 using an indigenously developed statistical model. According to the department, the model generally has an error margin of around four days.

To estimate the onset date, IMD analyses six atmospheric and climatic indicators. These include minimum temperatures over northwest India, pre monsoon rainfall activity over southern India, outgoing longwave radiation over the South China Sea and southwest Pacific region, and wind patterns over the southeast and northeast Indian Ocean.

Officials said the forecasting model has remained largely accurate over the last 21 years, except in 2015.

IMD Forecast Accuracy In Recent Years

Data released by IMD showed that in 2025, the monsoon reached Kerala on May 24, while the forecast date was May 27. In 2024, the monsoon arrived on May 30, against the predicted May 31.

In 2023, the actual onset took place on June 8, compared to the forecast date of June 4. Similarly, in 2022, the monsoon reached Kerala on May 29, while IMD had forecast May 27.

The advancement of the monsoon towards northern India is expected to gradually reduce heatwave conditions in several regions currently witnessing extreme temperatures.