Why IMD sees brief, intense rain spells as ‘early warning signs’ for North India

Barely a month later, on August 16, 2023, the Pong Dam on the Beas River received its highest-ever inflow of 7.30 lakh cusecs, surpassing the 1978 record. The dam level shot up by 25 feet in four days (August 11–15), flooding Kapurthala’s Mand region and parts of Hoshiarpur.

The pattern has continued this year. In August 2025, Himachal recorded 68 per cent above-normal rainfall — the highest for the month since 1949. Punjab also recorded 74 per cent surplus, the highest in 26 years. On August 16, Pong Dam again logged an inflow of 1.56 lakh cusecs, and its water level rose to 1,380.79 feet. Punjab’s rain surplus flipped from a deficit of 5 per cent to a surplus of 74 per cent in just a week (August 24–31). Haryana too went from deficit to 32 per cent surplus in the same span.

On September 2 this year, Ambala and Gurdaspur witnessed 105 mm and around 95 mm of rainfall in few hours, leaving the city completely inundated. Earlier episodes show this is not an aberration. In August 2019, a single day rainfall of 70 mm flooded 163 villages in Punjab’s Doaba. Shimla saw 118.6 mm of rainfall on July 4, 2018, while Gurgaon received 128 mm in just five hours on August 29, 2018. Una broke a 96-year record on July 9, 2023, with 228.5 mm of rainfall.

Experts said that there are several other examples of extreme spells of showers at various places in the past few years in North India and attributed them to climate change.

Why floods are worsening

IMD officials say the danger is not just the volume of rain, but its concentration in a few hours or days. “We are witnessing a month’s rainfall in a single day in some areas,” said Surinder Paul, Director, IMD Chandigarh. “Even two to three heavy spells are enough to cause floods now. Such frequency has increased sharply in the past decade, especially in August this year, when we saw three back-to-back extreme events.”

The sudden inflow leaves dams with little room, forcing emergency releases that flood downstream areas. The water in Pong Dam alone rose from 1,374 feet to 1,399.65 feet in four days in August 2023. Small seasonal streams, like the Sirsa, Swan and Budhki, also turn into torrents during these bursts, adding to the deluge.

Experts warn that weakened embankments, poor drainage, encroachment on natural waterways and inadequate reservoir management magnify the destruction. “Even moderate outflows are now inundating habitations because natural drainage paths no longer exist,” an IMD official said.

A study by Punjab Agriculture University (PAU), Ludhiana, suggests that a 68-year analysis (1951–2018) of Punjab’s rain shows a clear shift in seasonal patterns, with fewer rainy days but more intense downpours concentrated in shorter spans.

The study warns that rainfall concentration and extreme events are intensifying, posing fresh challenges for crop planning, groundwater recharge, and flood-risk management in Punjab.

Call for collective action

The IMD has urged governments in Punjab, Haryana, Himachal Pradesh, Chandigarh, and Jammu and Kashmir to treat these events as indicators of the “new normal” under climate change. “It is not the responsibility of one state alone,” said Paul, adding, “Since river systems are interconnected, monthly interstate coordination meetings are essential to plan water releases, strengthen infrastructure, and improve preparedness.”

IMD officials said that governments must work in the direction of harvesting a huge amount of rainwater by making big reservoirs so that this water can be used at the time of need later on to add to our groundwater.

They said our advanced cities are not future-ready ready as our sewer system should have the capacity to take 150 to 200 mm of rainfall, but currently even 50 mm to 60 mm of rainfall over a couple of hours floods cities for days.

The IMD stressed that prevention, early warning systems, and investment in climate-resilient infrastructure are critical. “If corrective measures are not taken,” an IMD official cautioned, “the floods we are seeing today could be far worse in the coming years.” As the Supreme Court has already said, because of the intense and frequent rain activities in Himachal, the region may vanish one day.

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