The southwest monsoon has officially arrived in India, making landfall over Kerala on Saturday, eight days earlier than its usual onset date of June 1, according to the India Meteorological Department (IMD).
This early arrival marks the swiftest onset of the monsoon in over a decade, the earliest since 2009 when the rains reached Kerala on May 23.
Over the past several days, the state has already seen a significant increase in rainfall activity, indicating the advancing monsoon conditions. The IMD uses three key criteria to declare the onset of the monsoon over Kerala:
- A minimum of 2.5 mm of rainfall recorded at 14 designated weather stations for two consecutive days,
- The presence of deep westerly winds up to the 600 hPa pressure level, and
- Outgoing Longwave Radiation (OLR) values dropping below 200 watts per square meter.
The early arrival of the southwest monsoon marks the beginning of the vital four-month rainy season that plays a critical role in India’s agriculture, water supply, and overall economic health.
The IMD has issued a red alert for Kerala and the Mahe region, warning of extremely heavy rainfall—defined as more than 205 mm in 24 hours—until Monday. Coastal Karnataka is also expected to experience similarly intense rainfall.
In tandem with the early monsoon, a well-marked low-pressure area in the Arabian Sea off the Konkan-Goa coast has intensified into a depression.
This system is expected to make landfall near Raigad, Maharashtra, by Saturday evening. Accompanying this development are strong monsoonal winds and squally conditions already affecting the region.
Looking ahead, the IMD has forecast an “above normal” monsoon this year. Rainfall is expected to reach about 105% of the Long Period Average (LPA) of 880 mm.
Supporting this prediction are two key ocean-atmospheric patterns—the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD)—both of which are currently in a neutral phase, favorable for monsoonal development.
The monsoon is projected to advance further into the remaining parts of southern and northeastern India, as well as central and eastern regions of the country, between May 29 and June 4.
This timely progression could provide a much-needed boost to early kharif crop sowing and overall water availability across the subcontinent.