The India Meteorological Department (IMD) confirmed on Saturday morning that the Southwest Monsoon has arrived over Kerala, marking an earlier-than-usual onset compared to the typical date of June 1. This year, the onset was recorded as the earliest since 2009, when the monsoon began over the Indian mainland on May 23, IMD data reveals.
According to the IMD, a well-marked low-pressure area over the east-central Arabian Sea, near the south Konkan coast, intensified into a depression. This system was centered over the east-central Arabian Sea and adjoining south Konkan coast on Saturday morning. It is expected to move eastwards and cross the coast between Ratnagiri and Dapoli during the forenoon as a depression.
This weather system has significantly enhanced rainfall activity over Kerala, contributing to the early onset of monsoon conditions.
How IMD Declares Monsoon Onset
The IMD uses specific criteria to declare the onset of monsoon over Kerala. These include:
- After May 10, if 60% of 14 designated stations — including Minicoy, Amini, Thiruvananthapuram, Punalur, Kollam, Allapuzha, Kottayam, Kochi, Thrissur, Kozhikode, Thalassery, Kannur, Kudulu, and Mangalore — record 2.5 mm or more rainfall for two consecutive days, the monsoon onset can be declared on the second day.
- Additionally, south-westerly wind patterns must be established.
- The Outgoing Longwave Radiation (OLR) must be low, indicating increased cloud cover and moisture.
These conditions were met, prompting IMD’s official declaration.
What This Means for India’s Monsoon Season
The early arrival of monsoon is a critical development for India’s agriculture and water supply. However, for a normal and sustained monsoon across the country, the formation of a ‘heat low’ over Northwest India is essential. This low-pressure trough helps pull moisture-laden winds inland, strengthening monsoon progression.
As reported by Hindustan Times on May 20, such a heat low has not yet formed, raising questions about the monsoon’s future strength and spread. Still, both IMD and independent meteorologists remain optimistic about timely and widespread monsoon coverage in the coming weeks.
