Image is for representational purposes only. | Photo credit: The Hindu
The Southwest Monsoon is expected to advance into Kerala on May 26, the India Meteorological Department (MD) said on Friday (May 15, 2026). The ‘normal’ date for the arrival of monsoon over the state is June 1.
Monsoon has almost arrived over Andaman and Nicobar Islands and Bay of Bengal, the IMD said in a press release. From there it is usually a 10-day journey to mainland India, although there can be various factors – such as a stirring cyclone – that can prevent this development.
Last year, the monsoon set over Kerala on May 24 – its first arrival since 2009. Although the date of arrival does not correlate with the amount of rainfall, rainfall is a cause for concern this year as the IMD and other weather agencies have warned of “below normal” rain.
The operational forecasts of the IMD regarding the onset date of monsoon over Kerala during the last 21 years (2005-2025) have been found to be correct except in 2015, the agency said in an information sheet. “Correct” here means that the monsoon will arrive within a window of four days from the forecast date.
The IMD has an elaborate criteria for declaring the onset of monsoon over Kerala, which includes a minimum number of meteorological stations covering Kerala and parts of Karnataka that register a prescribed amount of rain, wind speed and cloud density exceeding a certain threshold.
“So far we know that there will be heavy rains in the next five days after the onset of monsoon. The follow-up and progress can be reliably ascertained only after the (forecasting) models are subsequently run,” M. Ravichandran, Secretary, Department of Earth Sciences, told The Hindu.
India last saw reduced monsoon rainfall in 2023 – when the IMD warned of “near normal” rainfall at 96% of the long period average (LPA) – but in 2015 the IMD’s warning of below normal rainfall, at 93% of the LPA, proved to be an overstatement, with the actual worst rainfall in India being only 86% to one year of drought.
The main reason is the likely development of El Nino – a periodic warming of the central equatorial Pacific that has depressed India’s monsoon rainfall nine times in the 16 years it has occurred since 1950.
With fertilizer supplies disrupted ahead of the kharif season expected as a result of the war in West Asia, the lack of rain could impact agriculture, which is heavily irrigated.
Published – 15 May 2026 14:39 IST
