NEW DELHI: The India Meteorological Department (IMD) announced on Friday that the monsoon is expected to arrive in Kerala on May 26, signaling an early start to the rainy season in India. Typically, the southwest monsoon begins in Kerala around June 1, with a variation of about seven days.
“This year, the southwest monsoon is forecasted to set in over Kerala on May 26, with a model error margin of ± 4 days,” the IMD noted, highlighting that its operational forecasts regarding the onset date over Kerala have been accurate in 21 out of the past 21 years (2005-2025), except for the year 2015. The timing of the monsoon’s arrival does not affect its overall performance or distribution.
In 2022, the monsoon reached Kerala eight days earlier, on May 24. The IMD has predicted ‘below normal’ rainfall for this year, owing to concerns regarding the El Niño phenomenon, which is often linked to more intense summers and a weaker monsoon across South Asia.
The arrival of the monsoon in Kerala marks the commencement of the southwest monsoon across the Indian mainland, transitioning the region from hot and dry conditions to a rainy environment.
The IMD additionally indicated that conditions are favorable for the southwest monsoon to advance over parts of the south Bay of Bengal, the Andaman Sea, and the Andaman and Nicobar Islands within the next 24 hours.
Since 2005, the IMD has been providing forecasts for the monsoon’s onset date in Kerala, employing a domestically developed statistical model with a margin of error of ± 4 days. The model relies on six predictors: minimum temperatures in north-west India, the peak of pre-monsoon rainfall in the southern Peninsula, outgoing long wave radiation over the South China Sea, lower tropospheric zonal wind in the equatorial southeast Indian Ocean, outgoing long wave radiation over the Southwest Pacific Ocean, and lower tropospheric zonal wind in the equatorial northeast Indian Ocean.
