Keralam witnesses the 7th-lowest southwest monsoon season

The southwest monsoon has officially ended in Kerala and the state has recorded a 28% rainfall deficit – 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 seventh lowest southwest monsoon rainfall recorded in the state since 1901 and the fourth lowest since 2001.

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

Northeast Monsoon

The state is expecting some relief from the northeast monsoon, which usually occurs in mid-October. However, the latest forecast suggests that precipitation during the opening month of the season will be below normal, with precipitation developments expected to influence the emerging El Niño over the equatorial Pacific. South Kerala and parts of central Kerala may receive normal to slightly above normal rainfall during the northeast monsoon season as a whole, with more rain likely in November.

A characteristic feature of the southwest monsoon was its patchy distribution, characterized by fewer rain-producing systems over the Bay of Bengal and prolonged dry spells punctuated by occasional spells of high intensity. The trend was clearly visible in July. Kerala received only 853.8 mm of rainfall as of July 31 against the normal 1,301.7 mm, 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 of 1,374.9 mm for the period from June 1 to August 4, reducing the deficit to 23%.

A tropical storm in late July and a strong coastal depression during the first week of August triggered heavy rainfall in several parts of the state, including Idukki and Kottayam, while Wayanad witnessed a devastating debris slide. However, the spells did little to offset the overall deficit, with several pockets continuing to face the stress of rainfall. Long-term rainfall of low to moderate intensity is required for effective groundwater recharge. Such sustained rainfall was largely absent during the four-month monsoon season.

According to IMD climatologist VK Mini, the extended range forecast also does not indicate any heavy rainfall over Keralam during the next four weeks. However, central and south Keralam is expected to receive normal to slightly above normal rainfall in November and during the remainder of the northeast monsoon, 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 troughs and storms over the Bay of Bengal. El Niño, which is currently at near-record levels, could further affect rainfall patterns. Climate experts said prevailing oceanic and atmospheric indicators are consistent with a strong El Niño, which could support the formation of multiple weather systems over the Bay of Bengal or the Arabian Sea, raising hopes for an intense period interspersed with prolonged dry spells.

Published – 30 Sep 2026 22:18 IST