IMD confirms earliest Southwest Monsoon onset in Kerala since 2009 on May 24

The India Meteorological Department (IMD) confirmed the Southwest Monsoon's arrival in Kerala on May 24, 2025, marking the earliest onset since 2009 and eight days ahead of the normal June 1 date.

This early arrival is significant for India's agriculture, which supports about 42 percent of the population and contributes 18.2 percent to the GDP. The IMD forecasted above-normal rainfall at 105 percent of the long period average (LPA) of 880 mm for the season.

The monsoon onset was declared based on three criteria: rainfall of at least 2.5 mm at a minimum of 14 stations for two consecutive days, deep westerly winds up to 600 hPa, and a decline in Outgoing Longwave Radiation below 200 watts per square meter.

Heavy to very heavy rainfall (7-20 cm) with isolated extremely heavy rainfall (>20 cm) is expected from May 24 to 26, prompting red and orange alerts in multiple districts including Thiruvananthapuram, Wayanad, and Kozhikode.

The IMD warned of strong winds up to 50-60 kmph along coastal and interior areas, advising fishermen and residents to take precautions. Fishing bans have been imposed along the Kerala-Karnataka-Lakshadweep coasts until May 27.

The early monsoon arrival offers relief from ongoing heatwaves in northwestern India, where temperatures are expected to rise by 2-4°C in the coming days.

Authorities have imposed restrictions on water sports and trekking in landslide-prone areas, and quarry operations have been temporarily banned in some districts due to heavy rains and landslide risks.

"The monsoon is crucial for India’s agriculture sector, which supports the livelihood of about 42 percent of the population and contributes 18.2 percent to the country’s GDP," said the IMD.

This year's early onset follows a well-marked low-pressure system over the Arabian Sea, which intensified into a depression, increasing rainfall over Kerala.

The earliest recorded monsoon arrival in Kerala was May 11, 1918, while the latest was June 18, 1972. The 2025 onset is the earliest in 16 years, highlighting shifting weather patterns amid climate variability.

Overall, the IMD forecasts a robust monsoon season, critical for replenishing water resources and supporting agricultural productivity across the region.

The India Meteorological Department (IMD) confirmed the earliest onset of the Southwest Monsoon in Kerala since 2009, arriving on May 24, eight days ahead of the usual June 1 date. Heavy rains, strong winds, and red alerts have been issued across the state, with precautions advised for fishermen and tourists.