Keralam witnesses 7th-lowest southwest monsoon season

According to India Meteorological Department data, nearly 70% of the State remained significantly rain-deficient at the end of the season on September 30. Northeast monsoon, which normally sets in by mid-October, may be below normal during the opening month

Published - September 30, 2026 10:18 pm IST - THIRUVANANTHAPURAM

The southwest monsoon has officially ended in Keralam with the State recording a 28% rainfall deficit—it received 1,446.5 mm of rain against the normal 2,018.6 mm— leaving large parts of the State facing drought-like conditions.

This is the 7th-lowest southwest monsoon rainfall recorded in the State since 1901 and the fourth-lowest since 2001.

Idukki and Wayanad, two districts that account for a major share of Keralam’s large reservoirs and hydropower generation capacity, were among the worst-affected, each receiving around 50% less rainfall than normal. According to India Meteorological Department (IMD) data, nearly 70% of the State remained significantly rain-deficient at the end of the season on September 30 with eight districts recording deficits of 20-53% and six districts reporting deficits ranging from 0% to 20%.

The State is expecting that the northeast monsoon, which normally sets in by mid-October, may bring in some relief. However, the latest forecast indicates below-normal rainfall during the opening month of the season, with the emerging El Niño over the equatorial Pacific expected to influence the rainfall pattern. Southern Kerala and parts of central Kerala may receive normal or slightly above-normal rainfall during the northeast monsoon season as a whole, with more rain likely in November.

The defining feature of the southwest monsoon was its uneven distribution, marked by fewer rain-producing systems over the Bay of Bengal and prolonged dry spells punctuated by occasional high-intensity spells. The trend was clearly evident in July. Kerala had received only 853.8 mm of rain against the normal 1,301.7 mm by July 31, a deficit of 34%. However, heavy rainfall over four days, aided by a depression over central India, pushed the cumulative rainfall to 1,059.6 mm against the normal 1,374.9 mm for the period from June 1 to August 4, narrowing the deficit to 23%.

The tropical storm towards the end of July and a strong offshore trough during the first week of August triggered heavy rainfall in several parts of the State, including Idukki and Kottayam, while a devastating debris slip occurred in Wayanad. The spells, however, did little to offset the overall deficit, with several pockets continuing to face rainfall stress. For effective groundwater recharge, prolonged spells of low- to moderate-intensity rainfall are required. Such sustained rainfall was largely absent during the four-month monsoon season.

According to climate scientist V.K. Mini of the IMD, the extended-range forecast also does not indicate any major rainfall over Keralam during the next four weeks. However, central and southern Keralam are expected to receive normal to slightly above-normal rainfall in November and during the remaining part of the northeast monsoon season, which could help bridge the shortfall in October, she said.

Unlike the southwest monsoon, the northeast monsoon does not follow a regular pattern and is largely dependent on the formation and movement of depressions and storms over the Bay of Bengal. El Niño, which is currently at near-record levels, could further influence the rainfall pattern. Climate experts said the prevailing oceanic and atmospheric indicators are consistent with a strong El Niño, which could favour the formation of more weather systems over the Bay of Bengal or Arabian Sea, raising hopes of intense spells interspersed with prolonged dry periods.

Published - September 30, 2026 10:18 pm IST

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