Monsoon Misses May 26 Arrival Forecast In Kerala: Here's When It Is Expected Now

Last Updated:May 27, 2026, 14:39 IST

While heavy showers have already lashed parts of Kerala, the IMD says the technical conditions required to declare the official onset of the monsoon have not yet been fully met.

After days of anticipation, the southwest monsoon has still not officially reached Kerala, even though the India Meteorological Department (IMD) had earlier forecast its onset around May 26. The delay has sparked questions over whether India is heading into a weaker or erratic rainy season, especially with concerns growing over a developing El Nino pattern in the Pacific Ocean.

While heavy pre-monsoon showers have already lashed parts of Kerala, the IMD says the technical conditions required to declare the official onset of the monsoon have not yet been fully met. According to the weather department, the monsoon is now likely to arrive between June 2 and June 4.

What Happened To The May 26 Monsoon Forecast?

On May 15, the IMD had predicted that the southwest monsoon would hit Kerala on May 26, nearly a week earlier than the normal onset date of June 1. The department had also clarified that the forecast carries a “model error" margin of plus or minus four days. IMD Director General Mrutyunjay Mohapatra had said the forecast was based on an indigenous statistical model that uses six meteorological parameters, including wind patterns, outgoing longwave radiation and pre-monsoon rainfall activity.

However, meteorologists say the atmosphere has not behaved as expected over the last few days. Weak cross-equatorial winds, insufficient cloud organisation and changing wind patterns over the Arabian Sea have slowed the monsoon’s progress toward the Kerala coast.

Has The Monsoon Been Delayed?

Technically, monsoon has not yet been delayed. The IMD considers June 1 as the normal date for monsoon onset over Kerala. Since the current revised window still falls close to that benchmark, meteorologists are treating this more as a “missed early arrival" rather than a major delay.

Weather experts also caution that the onset date alone does not determine how strong the entire monsoon season will be. India has previously seen years where an early onset was followed by weak rainfall, and vice versa.

Last year, for instance, the monsoon had arrived over Kerala on May 24, eight days ahead of schedule. This year’s slower progress, therefore, stands out sharply in comparison.

What Conditions Are Needed For Monsoon Onset?

The IMD officially declares the onset of the southwest monsoon over Kerala only after a combination of meteorological conditions are satisfied. These include sustained rainfall over designated weather stations in Kerala and nearby regions, strong westerly winds at lower atmospheric levels, consistent clouding and deep convection over the Arabian Sea, and specific outgoing longwave radiation (OLR) values that indicate organised rainfall activity.

Meteorologists say that while Kerala has received intense rainfall spells recently, the larger wind and cloud patterns needed for a formal declaration have remained inconsistent.

Is El Nino Already Affecting The Monsoon?

A developing El Nino remains one of the biggest concerns this year. El Nino refers to the warming of sea surface temperatures in the central and eastern Pacific Ocean. Historically, many El Nino years have been associated with weaker monsoons and higher temperatures across South Asia.

Several weather reports and forecasters have warned that the evolving El Nino conditions may affect both the pace and distribution of rainfall this season. The IMD has in fact predicted a below normal monsoon this year.

Heavy Rain Continues Despite Official Delay

Interestingly, even without the formal onset announcement, Kerala has continued to witness widespread rainfall activity. The IMD has issued yellow alerts across districts in the state due to the possibility of heavy rain and thunderstorms. The IMD has also indicated that conditions remain favourable for the further advance of the monsoon over the Arabian Sea and adjoining regions in the coming days.

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