July hoodwinked weather experts in India. Despite the India Meteorological Department (IMC) forecast of a below-normal season driven by ‘Super El Nino’, July turned out to be unexpectedly wet, showing how climate change and changing ocean-atmosphere interactions were making the Indian monsoon harder to predict.
India received 283.3 mm of rainfall in July against a normal of 280.5 mm, after IMD’s June 30 forecast had put July rainfall at less than 94 per cent of the Long Period Average (LPA). The seasonal deficit narrowed from 35.4 per cent at the end of June to 13 per cent for the June-July period. The IMD, in its briefing end of July, said below-normal rainfall was very likely over many parts of the country in August-September, except some parts of peninsular India, central India, northern parts of northwest India, and east and northeast India.
Yet that is bad news as the rains have not arrived as steady showers spread over the weeks, but extreme bouts of downpours leading to flooding, loss of lives, and damage to property and agricultural prospects.
Mrutyunjay Mohapatra, director general of meteorology, IMD, said India recorded 269 extreme heavy rainfall events and 918 very heavy rainfall events in July. He said the extremely heavy count is much higher than previous years, but flagged that one factor could be the increase in the number of rain gauges IMD monitored in 2026. For context, IMD’s gauge network went up from 3,980 in 2015 to 6,727 in 2025, alongside a shift to block-level monitoring across 7,200 blocks.
Akshay Deoras, a research scientist at the National Centre for Atmospheric Science at the University of Reading, United Kingdom, said the monsoon is being driven by its own internal machinery rather than the external modulators that forecasters keep a watch on. Low-pressure systems are the internal factor. Under the gloomy scenario of El Nio, oceanic parameters MJO (Madden-Julian Oscillation) and IOD (Indian Ocean Dipole) are the two defence systems for the southwest monsoon.
Both weather phenomena, if in a positive phase, are variably related to good monsoon rains over the country and are known for negating the effect of El Nio up to large extent. “It seems the monsoon is driving on its own, and this is where the role of climate change cannot be ruled out,” Deoras said.
Heavy to extremely heavy rainfall battered several parts of the country, particularly Maharashtra, Gujarat, Assam, Odisha, Jammu & Kashmir and Himachal Pradesh. As of July 29, 15 states had recorded normal rainfall and four states excess to large excess rainfall, covering 60 per cent of the state area of the country.
Meanwhile, 17 states recorded deficient rainfall, accounting for 36 per cent of the country’s state area. Umbergaon in Gujarat’s Valsad recorded 1,064 mm of rainfall in 24 hours in late July, which Deoras said was the third highest 24-hour rainfall recorded in India since 1901.
Back-to-back weather systems kept the monsoon current active through the month. K.J. Ramesh, former director general of IMD, said the existing models saw none of it coming. “Clearly, none of the climate models captured these phenomena,” he said. He identified two drivers. Warming in the West Pacific, west of the Philippines, has offset El Nio’s rainfall-suppressing potential, pushing three cyclonic circulations through Myanmar. Their remnants have entered the North Bay of Bengal and re-intensified, spreading heavy rain along their track across the peninsula,” he said.
“Separately, an increase in Western Disturbances during the monsoon season has loaded more moisture from the Arabian Sea into Maharashtra and Gujarat. Those systems are travelling as far as Tibet, raining over the eastern Himalayas and feeding the floods in Assam. Climate change is reshaping the characteristics of the monsoon, which [existing] models are failing to take into account,” Ramesh added.
IOD, which is also known as Indian Nio, is an irregular oscillation of SSTs (sea surface temperatures) wherein the western Indian Ocean becomes relatively warmer and makes the eastern side colder. This also affects the strength of the monsoon over the Indian subcontinent. A positive phase sees greater-than-average SST and more precipitation in the western Indian Ocean region, with a corresponding cooling of waters in the eastern Indian Ocean. While neutral IOD conditions do no harm monsoon rains, negative IOD brings opposite conditions. SST variation in the Indian Ocean is becoming increasingly important in assessing climate variability.
The IMD statement says, “Currently IOD conditions prevail over the Indian Ocean, and indications are that neutral IOD conditions are likely to persist throughout the remaining period of southwest monsoon season. However, climate forecasts from some international forecasting centres suggest that positive IOD conditions are likely to develop during September 2026.”
This year is another reminder that India’s monsoon is entering a new climate regime. Traditional drivers such as El Nio remain important, but they are increasingly interacting with warmer oceans, changing atmospheric circulation and climate change in ways that existing models struggle to capture. The challenge ahead is not simply forecasting how much rain will fall, but understanding where, when and how intensely it will fall in a rapidly warming world.
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