The southwest monsoon is likely to arrive over Kerala on May 26, according to the India Meteorological Department (IMD).
The southwest monsoon normally arrives in Kerala around June 1 and this marks the official onset of the monsoon season in India. According to the IMD, it is an important indicator characterising the transition from the hot and dry season to the rainy season. The Met department then advances northwards to cover other parts of the country. "As the monsoon progresses northward, relief from scorching summer temperatures is experienced over the areas," it added.
In 2025, the onset of the monsoon was recorded on May 24. IMD has been issuing monsoon onset forecasts over Kerala from 2005 onwards and the statistical system has a model error of ±4 days. According to the Met department, its predictions on monsoon onset over Kerala went wrong only once in the past 21 years, which was in 2015.
"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. This means the monsoon could arrive as early as May 22 or as late as May 30.
How is monsoon predicted?
The weather office uses six predictors for its onset forecast. These include minimum temperatures over northwest India, pre-monsoon rainfall peak over southern peninsula, Outgoing Long-wave Radiation (OLR) over South China Sea, OLR over Southwest Pacific Ocean, lower tropospheric zonal win over equatorial southeast Indian Ocean and upper troposheric zonal wind over equatorial northeast Indian Ocean.
How a weak monsoon could impact Indian economy?
The India Meteorological Department said India might get below-normal rainfall this monsoon season due to El Nino conditions. Around 80 cm of rainfall is expected in the monsoon months, while the long-period average (1971-2020) of seasonal rainfall is 87 cm.
A below-normal monsoon could threaten negatively impact kharif crops like rice, soybeans and cotton. Lower agricultural yield would constrict food supplies, resulting is surge in food inflation. Nearly half the Indian population relies on agriculture for livelihood and hence a weak monsoon could suppress rural incomes and spending. Rural demand squeeze mostly affects sales of fast-moving consumer goods (FMCG) as well as the automobile sector, especially tractors and two-wheelers.