The Southwest monsoon had entered the Andaman Sea on May 16, but its advance towards the mainland was slower than expected.

The India Meteorological Department (IMD) had forecast its onset over Kerala by May 26, with a model error of plus or minus four days; the normal onset date is June 1. The monsoon had missed both markers, eventually setting in over Kerala only on June 4.

What it brings with it, however, offers little comfort.

National projection

According to projections presented by O.P. Sreejith, Scientist and Head, Climate Monitoring and Prediction Group, Climate Research and Services, IMD, Pune, the IMD’s updated long-range forecast, released on May 29, projects the season’s rainfall over the country as a whole at 90% of the Long Period Average (LPA), with a model error of plus or minus four percentage points. The accompanying five-category probability forecast puts the combined chance of deficient or below-normal rainfall nationally at 84% this year.

Bharati Sabade, Scientist at the Cyclone Warning Centre, Visakhapatnam, said the underlying signal is already visible in the data. “The observed values of sea surface temperatures above the 0.5 threshold point towards an El Niño,” she said.

For Andhra Pradesh, the numbers carry particular weight. Coastal Andhra Pradesh is forecast to receive below-normal rainfall, at less than 91% of its LPA, or roughly 547.4 mm against a seasonal normal of 601.3 mm. Rayalaseema’s outlook is starker: below 88% of LPA, or about 358.0 mm against a normal of 408.5 mm.

The State as a whole falls into the below-normal category against a four-month normal of 521.6 mm. June, which sets the tone for sowing, is expected to be the most deficient period, with rainfall projected at below 79% of LPA, or 86.9 mm against a normal of 94.1 mm, accompanied by above-normal maximum and minimum temperatures across most parts of the State.

Behind these figures lies a transition underway in the equatorial Pacific. The IMD notes that neutral conditions are shifting towards El Niño, with models indicating that the phenomenon is likely to develop and persist through the season. The Indian Ocean Dipole, by contrast, remains neutral and is expected to stay that way.

Professor C.V. Naidu, Head, Department of Meteorology and Oceanography, Andhra University, explained the Pacific mechanics driving this year’s outlook.

The Southern Oscillation, he said, describes a seesaw in atmospheric pressure between Tahiti in the central Pacific Ocean and Darwin in northern Australia. “Tahiti pressure minus Darwin pressure is quantified as the Southern Oscillation Index. If it is positive and persistent, it is called La Niña; if it is negative and persistent, it is called El Niño,” he said.

The result is a weakening of the trade winds that carry moisture towards India. “Why are we afraid of El Niño? Because the trade winds weaken,” he said, adding that the moisture-bearing Somali Jet, which crosses the equator off the Somali coast and feeds the monsoon, depends on a strong north-south temperature gradient that El Niño disrupts.

The atmospheric stability that follows, he noted, is “good for humans, but for the atmosphere, it must be unstable” for rainfall to occur.

Mr. Naidu pointed to the Indian Ocean Dipole as a mechanism that, under different conditions, could partly offset the Pacific-driven deficit. “This activity in the Indian Ocean might help in covering some of the deficit if the IOD is positive,” he said. However, he added that current trends did not support this outcome.

Mr. Naidu pointed to a weather trough currently active over the region as a possible local cushion, attributing recent rainfall across the State, including Rayalaseema and Coastal Andhra, to it. However, he stressed that this was a short-term, localised development and not a revision of the seasonal deficit indicated by the IMD forecast. He was unequivocal about the stakes ahead.

“The upcoming months of July and August are very crucial. These are prime monsoon months. If this deficit continues during these months, it will cause a problem. Crops will get damaged,” he said.

The historical record complicates a simple reading of El Niño years as drought years for the State. Of the 17 El Niño years between 1951 and 2023, Andhra Pradesh recorded above-normal seasonal rainfall in three. What worsens this year’s outlook, in Mr. Naidu’s assessment, is the overlay of global warming on a naturally recurring cycle.

“Because of global warming, dry days will increase, and very heavy rainfall events will increase,” he said, describing localised cloudbursts in which “rainfall that should fall over a 100 sq. km area falls in just 10 sq. km, resulting in flash floods.”

Unchecked groundwater extraction

The human cost, he said, is already measurable. “If the temperature increases, heart problems will increase,” he said, adding that sustained heat disrupts appetite and hydration, and that replacing water or buttermilk with aerated drinks leaves “the digestive system completely ruined.” The psychological effects, he argued, are equally significant. “When temperature increases, it brings intolerance and imbalance to your mental state.”

Visakhapatnam’s Kotha Road junction, he said, illustrates how urban design compounds the problem by trapping heat, while unchecked groundwater extraction threatens saltwater intrusion that could permanently degrade the city’s water table.

His prescriptions were practical rather than sweeping: plant trees in every available space, resist paving over open ground, deepen reservoirs such as Mudasarlova, and use public transport at least two days a week.

“Water should be used very carefully and sparingly this year. If you need a bucket of water for a bath, use only half a bucket,” he said.