Climate change is shrinking India’s weather forecast window, says IMD chief

“If I could earlier predict heavy rainfall three days in advance, now I may only be able to forecast it one and a half days ahead," he said. “That’s the impact climate change is having on our systems."

Mohapatra noted that the frequency, intensity, and duration of heat waves have risen in India’s heat-core zones across north and central India. At the same time, central and peninsular India are witnessing more heavy rainfall events, while lightning and thunderstorms have become more frequent in eastern and northeastern states.

These shifts carry widespread consequences.

Extreme weather, ranging from cyclones and droughts to hailstorms and floods, not only endangers lives and civic infrastructure but also disrupts food supply chains, pushing up prices of fruits and vegetables and adding to inflationary pressures. Climate risks also weigh heavily on insurers, who must contend with rising claims due to lightning-related deaths and property damage.

India’s 2024-25 Economic Survey warned that heat and water stress could significantly affect crop yields, threatening the country's food security.

According to Mohapatra, 2024 was the warmest year on record. “If you look at the warmest years in the past 120 years, most of them have occurred in the last two decades," he said. “This is not just about extreme weather. It can also affect socio-economic conditions."

A recent report by the Centre for Science and Environment, a Delhi-based think tank, underlines the rising frequency of such events. In the first nine months of 2024, India recorded extreme weather on 255 out of 274 days—93% of the time. These events caused 3,238 deaths, damaged over 235,000 homes and buildings, destroyed crops across 3.2 million hectares, and killed nearly 9,500 livestock.

The ongoing monsoon season has further highlighted the growing toll. In Himachal Pradesh, torrential rains since 20 June triggered cloudbursts, landslides, and flash floods. At least 80 people have died in rain-related incidents, 38 are missing, and more than 120 have been injured, according to the State Emergency Operations Centre. Roads, bridges, and public infrastructure have suffered widespread damage.

Despite the growing unpredictability, Mohapatra pointed out that the IMD’s forecast accuracy has improved significantly over the last decade. “In the past 10 years, our forecasting accuracy has increased by 40% to 50%, even with climate change in the backdrop," he said. “That’s because we’ve upgraded our observation systems, modelling, communication, forecasting and early warning capabilities."

Mohapatra also noted that severe cyclonic storms over the Arabian Sea have been on the rise since the 1990s—a trend aligned with broader climate models.

Meanwhile, western disturbances—crucial for India’s winter rainfall—are showing a declining trend. These moisture-laden storms from the Mediterranean region are vital for snowfall and winter rains across north India, particularly in Punjab, Haryana, Rajasthan, Uttar Pradesh, and Jammu & Kashmir.

This precipitation supports rabi crops such as wheat and barley and sustains water reservoirs through snowmelt. “The declining frequency of western disturbances due to climate change could impact not just water availability but also crop productivity," Mohapatra said.