India's driest monsoon since 2015; West Bengal, Kerala among states badly hit by rain deficit

India formally concluded its four-month south-west monsoon season as the driest in over a decade. Overall seasonal rainfall reached 87 per cent of the Long Period Average (LPA), leaving a national precipitation deficit of 13 per cent. Total rainfall measured 759.4 mm against the normal benchmark of 868.6 mm, which is calculated over a 50-year historical average. Not since 2015 has seasonal rainfall dropped below 90 per cent of normal levels.

Fifteen out of 36 states and Union Territories, accounting for 40 per cent of the country's geographical area, recorded below-normal rain. Of the 36 meteorological subdivisions, 17 finished with deficient rainfall, 18 recorded normal rainfall, and only one reported excess rain. Out of 741 districts nationwide, 313 suffered deficits of at least 20 per cent. In addition, 217 districts received under 70 per cent of their normal rain, with 71 districts getting half or less of their seasonal quota.

How the season unfolded month by month

Meteorological authorities issued early warnings in April, predicting a below-normal monsoon. What followed was a volatile four months. June opened with a crushing 35 per cent rainfall shortfall across the country. Conditions recovered briefly in July, which delivered a modest 1 per cent surplus above normal levels.

However, dry weather returned in August with a 16.3 per cent deficit. September brought limited late relief, ending 7.6 to 8 per cent below normal as late showers helped narrow the overall seasonal deficit slightly. By late September, the withdrawal of the monsoon had stalled for a week.

Why ocean warming disrupted the weather

The main cause of the erratic rainfall was El Niño, an ocean phenomenon marked by abnormal warming in the surface waters of the equatorial Pacific Ocean. The Niño 3.4 index reached 2.72, higher than the 2.14 recorded during the 2015 drought. Global weather bodies declared El Niño's onset in June, warning it could become one of the strongest ever recorded.

This severe warming was partly countered by a positive Indian Ocean Dipole (IOD) entering the positive zone at 0.76. Warming in the Indian Ocean helped cushion and offset some of the severe dry conditions late in the season.

How different regions fared across the country

Precipitation varied significantly across the country. East and North-East India, including West Bengal, Bihar, and Jharkhand, saw the highest deficit at 25 to 26 per cent below normal. Southern states—comprising Kerala, Tamil Nadu, Karnataka, Telangana, and Andhra Pradesh—recorded a 24 per cent deficit.

North-West India, covering Punjab, Haryana, Rajasthan, and Uttar Pradesh, faced a 6 per cent deficit. Central India, comprising Maharashtra, Gujarat, Madhya Pradesh, Odisha, and Chhattisgarh, ended close to normal with a 2 to 3 per cent deficit.

What risks and challenges lie ahead

The monsoon deficit has created distinct challenges for farming and water storage. Overall kharif crop sowing dropped 1.2 per cent year-on-year to 110.8 million hectares, driven mainly by a 3.6 per cent drop in paddy planting down to 43.1 million hectares. Cultivation of maize, arhar, soyabean, and paddy faced downward pressure, forcing official cuts to foodgrain harvest targets. Total pulse acreage rose 2 per cent due to higher urad and arhar planting, though moong acreage fell 3.7 per cent.

States with low irrigation coverage—including Odisha, Chhattisgarh, Madhya Pradesh, and Uttar Pradesh—face heightened agricultural vulnerability. Water security presents another major hurdle. Reduced farm output and high input costs threaten rural consumption, while tightening food supplies increase domestic and global inflation risks for cereals and oil.