Super El Niño Can’t Explain Mumbai’s Deluge, But Climate Change Can
Climate change is intensifying Mumbai’s rainfall, making downpours shorter and more extreme. Experts explain why El Niño alone cannot explain the floods.
Mumbai Climate Change Rainfall: Mumbai’s recent deluge reflects a changing monsoon shaped by climate change as much as El Niño. Experts say warming oceans and a hotter atmosphere are driving fewer rainy days but far more intense downpours, exposing the city’s ageing drainage systems and growing vulnerability to urban flooding.
For most of June, the story of India’s monsoon was one of delay and deficit. A strengthening El Niño in the Pacific was pushing the Southwest Monsoon back, and by the end of the month the country was staring at a 40 percent rainfall shortfall. Then, within days, the sky flipped. As the monsoon shifted into an active phase, Mumbai and the rest of India’s west coast were hit by rain so intense that the national deficit collapsed from 40 percent to 20 percent in less than a week, as of July 6.
The whiplash has revived a debate among climate scientists that goes beyond this one season: it is no longer only about how much rain a city gets, but how that rain arrives.
A new briefing from Climate Trends lays out the case that a warmer atmosphere and rapidly heating oceans are loading the air with more moisture than before, which means fewer rainy days overall but far more violent bursts when the rain does come. El Niño, in this reading, still controls the timing and broad strength of the monsoon — but climate change is increasingly writing its character, turning downpours shorter, sharper, and more likely to overwhelm drains built for a gentler era.
Mumbai’s own numbers make the point. In the first seven days of July alone, the city saw four separate spells of triple-digit rainfall. The Colaba observatory logged 791 mm between July 1 and 7 — more than its entire climatological average for the whole month of 768.5 mm. Santa Cruz recorded 879 mm in the same window, brushing up against its monthly normal of 919.9 mm.
Mahesh Palawat, Vice President of Meteorology and Climate Change at Skymet Weather, pointed to a pile-up of weather systems as the immediate trigger. “Monsoon is presently in an active phase, with several weather systems prevailing across the country,” he said, noting a depression over Odisha and a cyclonic circulation over Maharashtra keeping both arms of the monsoon active, while continuous moisture from the Arabian Sea kept regenerating cloud cover over the state.
Dr Raghu Murtugudde, Emeritus Professor at the University of Maryland and a retired professor at IIT-Bombay, went further, arguing that the two forces driving this monsoon can no longer be pulled apart. “El Niño just cannot be separated from global warming anymore,” he said, describing how both the Arabian Sea and the Bay of Bengal were firing at once, feeding moisture into the core monsoon zone that eventually rides the Western Ghats and dumps over Mumbai.
Rewriting the Monsoon’s Rulebook
Palawat said the shift is structural, not a one-off. Weather systems that form in the Bay of Bengal, he explained, have started tracking west instead of northwest, while the Arabian Sea’s record warming has added extra moisture to the mix, keeping clouds regenerating for days on end wherever a weather system parks itself.
Dr K J Ramesh, former Director General of the India Meteorological Department, framed it as a break from the monsoon India used to know. “We know that the character of the monsoon has changed forever due to global warming,” he said. “Rains will be in the form of short duration and high intensity, whether there is an El Niño or no El Niño.” He pointed to Rajasthan, Gujarat and West Madhya Pradesh, where Western Disturbances alone can no longer explain the volume of rain now falling — an added moisture feed from the Arabian Sea, he said, has changed the pattern across the region.
Research cited in the briefing backs this up on a larger scale: the Middle East has been warming almost twice as fast as the rest of the inhabited world, and that heating has been linked to nearly half — 46 percent — of the intensified rainfall over Northwest India and Pakistan between 1979 and 2022, by pushing moisture northward out of the Arabian Sea.
The Long-term Drift
Zoom out from any single storm and the trend holds. Comparing 1981–2000 with 2001–2024, average monsoon rainfall has climbed by nearly 15 percent in Mumbai and 23 percent in Pune, according to data from the Council on Energy, Environment and Water (CEEW).
Looking ahead, a separate report — Indian Coastal Region: Climate Projections 2021–2040 — suggests suburban Mumbai and parts of coastal Maharashtra and Gujarat should expect almost an additional week of heavy rain during the Southwest Monsoon in the coming years, alongside a projected 18 percent rise in the region’s already-massive 1,749 mm monsoon baseline. The same projections point to rising temperatures across the board, including a 1.3°C increase in both summer wet-bulb and winter minimum temperatures.
When Rain meets a City That isn’t Ready
Climate change, though, is only half the story of why Mumbai floods. The briefing frames urban flooding as a climate-plus-exposure problem — extreme rainfall colliding with a city whose drains, floodplains and green cover haven’t kept pace.
Ramesh was blunt about what that means on the ground. “It is no longer a matter of warnings anymore as substantial warnings have been issued well in time. It is now a preparedness and response issue,” he said, calling for full desilting of drains ahead of every monsoon and blaming unchecked concretisation for leaving trees with no room for their roots to breathe.
Dr Vishwas Chitale, a Fellow at CEEW, described the immediate toll of the past week’s rain — an orange alert in Mumbai and a red alert in Pune, both signalling rainfall heavy enough to disrupt daily life. He pointed to early warning systems and structured flood-resilience plans, like the one CEEW helped develop with the Thane Municipal Corporation, as the kind of groundwork cities now need. “We need to come out with some practical solutions on the ground to be able to manage urban flooding better,” he said.
Aarti Khosla, Director of Climate Trends, put the challenge in starker terms: extreme rainfall is no longer a possibility to plan around but a near-certainty to plan for. “The question is no longer whether extreme rainfall events will occur, but whether our cities are prepared to withstand them,” she said, calling for climate-resilient drainage, nature-based flood defences and urban planning that treats risk as a starting assumption rather than an afterthought.
The briefing’s broader point is a simple one: urban flooding happens when saturated drainage meets any of several triggers — torrential rain, storm surge, sea-level rise, groundwater seepage, or simply a city with too little permeable ground left to absorb water. Global warming is intensifying the rainfall trigger, and dense, paved-over cities are amplifying what happens next.
As one line from the briefing puts it, cities designed for yesterday’s climate are struggling to cope with today’s extremes — and, if the projections hold, tomorrow’s will demand even more.
Dipin Damodharan is an award-winning journalist, editor and media entrepreneur, and Co-founder and Editor-in-Chief of EdPublica, an independent global media platform covering education, science, research, innovation, climate and public policy. With more than a decade of experience in journalism, he has worked across print, digital and multimedia media. His reporting explores science, climate, sustainability and the social impact of research and innovation. His work has been recognised by the Solutions Journalism Network and other journalism organisations.
The Matterhorn rises above the Alpine landscape in Switzerland, with patches of snow visible on its slopes. Image Credit: Pexels
Switzerland’s iconic Matterhorn has lost almost all of its snow cover after an exceptionally hot and dry summer, offering a stark visual sign of the rapid changes unfolding across the Alps.
The 4,478-metre Matterhorn, one of Switzerland’s most recognisable peaks, was photographed in late September with large areas of bare rock where snow would normally be visible. Experts say the lack of snow at such high elevations is highly unusual for this time of year.
The Matterhorn’s appearance comes as Switzerland records another year of severe glacier melt. According to the Swiss Glacier Monitoring Network (GLAMOS) and the Swiss Academy of Sciences, Swiss glaciers lost more than 5 per cent of their ice volume in 2026, making it the second-largest annual percentage loss on record.
The scale of the loss is particularly significant because Switzerland’s glaciers have already shrunk dramatically. Nearly 20 per cent of the country’s glacier volume has disappeared in just five years, according to the latest monitoring data. Some smaller glaciers have disappeared completely.
Record heat and little winter snow
Scientists say the severe melt was driven by a combination of unusually low snowfall during the winter of 2025–26 and repeated heatwaves between May and September.
The winter was among Switzerland’s 10 least snowy since measurements began. During the summer, the freezing level remained above 4,000 metres for 76 days, more than twice the average and a Swiss record. By September, snow had disappeared even at elevations of around 3,500 metres.
Snow plays an important role in protecting glaciers. A layer of fresh snow reflects sunlight and shields the darker ice underneath from melting. It also provides the material needed to replenish glaciers over time. With less snow accumulating during winter, glaciers are left increasingly exposed to summer heat.
The consequences have been substantial. The average thickness of individual Swiss glaciers declined by between 2.5 and 4 metres this year, while some glacier tongues lost as much as 10 metres of ice. The Aletsch, Rhône, Allalin and Clariden glaciers recorded their greatest melt on record in 2026.
More than a changing landscape
The disappearance of snow and ice is not only transforming the appearance of the Alps. Between July and September, Swiss glaciers released around 2.2 trillion litres of water as they melted more than four times the annual drinking-water consumption of Swiss households. For now, this meltwater can help ease summer water shortages, but scientists warn that this benefit will diminish as the glaciers continue to shrink.
The Alps are also an important source of water for major European rivers, including the Rhine, Rhône, Po and Danube. Switzerland also relies heavily on hydropower, making changes in glacier and snowmelt relevant beyond the mountains themselves.
The snow-free Matterhorn therefore represents more than an unusual photograph. It is one visible sign of a much larger transformation in the Alpine environment that scientists say is being accelerated by rising temperatures and changing snowfall patterns.
Climate Change Is Already on Your Dinner Table. Here Is How It Got There
Climate change is already affecting what food costs. From heatwaves and droughts to weaker crop yields, extreme weather is disrupting food markets and making staples such as potatoes, tomatoes and other vegetables more price-sensitive.
A farmer works among young rice seedlings in a waterlogged field, highlighting the vulnerability of agriculture to extreme weather and changing rainfall patterns. Image Credit:Pexels
From heatwaves in the field to prices in the market, extreme weather is changing what food costs. Perishable foods such as vegetables are especially exposed, and India’s coming potato season is one to watch.
What does climate change have to do with the tomatoes in your salad or the potatoes on your plate? More than it may seem.
Climate change is not only about rising temperatures or intense rainfall. Its effects also move through farms and food markets and, eventually, into our kitchens. Heatwaves, droughts and uneven weather are disrupting the food system. People already stretched by work and the cost of living then find that food has become dearer still.
The result is a climate story that is easy to overlook because it shows up in an ordinary place: the dinner table.
A growing body of research is beginning to map the journey from climate shock to food price. A September 2026 analysis by Zero Carbon Analytics found that extreme climate events are raising agricultural risks, disrupting food systems and pushing up food prices. It also highlights the vulnerability of perishable, nutrient-dense foods, naming tomatoes in the Mediterranean among the affected commodities.
That matters because the climate-food connection is not simply about whether there will be enough calories on the planet. It is also about what those calories cost and what people can afford to eat.
The problem starts in the field
A 2021 study in the Journal of Environmental Economics and Management examined global yields of major calorie crops, using gridded agricultural data and climate-model projections. The researchers found that, without adaptation beyond what farmers have historically managed, climate change could cut global crop yields by 3–12 per cent by the middle of the century and by 11–25 per cent by the end of it, under a vigorous warming scenario. They also found that farmers’ historical adaptation has only slightly softened the effects of weather shocks across broad regions.
That does not mean every crop, country or farm will see the same decline. Impacts vary with crop type, location, irrigation and local conditions. But the research points to a larger problem: agriculture cannot be separated from a changing climate. The study covers staple calorie crops rather than vegetables, and the humble potato offers a closer example.
Why potatoes are vulnerable
Potatoes may look ordinary, but growing them depends on a narrow combination of temperature and water. The Intergovernmental Panel on Climate Change (IPCC) cites modelling that projects global potato-yield reductions of 2–6 per cent by 2055, though the impact varies considerably between regions. In some marginal growing areas the projected fall in tuber dry weight is much larger, while some high-yielding environments could see gains.
The same assessment cites modelling in which potato yields fall by about 4.6 per cent for every 1°C rise in temperature, and by about 2 per cent for every 10 per cent fall in rainfall at non-irrigated sites.
For India, this makes the coming potato season worth watching.
A 2025 study in Environmental Research Letters found that potato prices in India rose by about 81 per cent between April and June 2024, compared with the same period a year earlier, after an unusually severe heatwave in May. Onion prices rose by 89 per cent over the same period.
Farmers harvesting potatoes.Image credit:Pexels
This year’s southwest monsoon has been weak. India had received about 86 per cent of its normal rainfall by 29 August, according to India Meteorological Department data, and Bihar, an important potato-producing state, was running about 40 per cent below normal at the end of the month.
Analysts caution, however, that this does not amount to a confirmed national loss in potato production. The main risk is what the shortfall leaves behind: lower soil moisture, weaker groundwater recharge and higher irrigation needs before the winter crop is planted.
Nor have the shops felt it yet. Official consumer-price data for August 2026 show potato prices 13.14 per cent lower than a year earlier and tomato prices 31.09 per cent lower, although onions were 48.27 per cent dearer.
That distinction matters. Climate science can identify elevated risks; it does not mean every weather event automatically produces a specific crop loss or price rise.
How climate shocks reach the market
Tomatoes illustrate another part of the problem. Fresh vegetables are particularly exposed to climate shocks because they are perishable and have limited storage windows.
Zero Carbon Analytics counts tomatoes among the foods whose prices have been affected by recent climate extremes, and points to wider evidence that extreme weather can produce sharp price movements in nutrient-dense foods.
The Environmental Research Letters study also examined reported food-price spikes associated with extreme heat, drought and heavy rainfall. The examples are striking. South Korean cabbage was 70 per cent dearer in September 2024 than a year earlier. Vegetable prices in China rose 30 per cent between June and August 2024. In the United States, extreme heat and drought in California and Arizona contributed to an 80 per cent year-on-year rise in vegetable producer prices by November 2022.
In southern Europe, drought was associated with a 50 per cent year-on-year rise in olive-oil prices by January 2024. Global cocoa prices rose by almost 300 per cent by April 2024 compared with a year earlier, after a heatwave in Ghana and Côte d’Ivoire.
These figures should not be read as saying that climate change alone caused every increase. The researchers note that demand, transport disruptions, speculation and other socioeconomic factors can also shape the final price. But their analysis shows how extreme climate conditions can trigger food-price shocks.
From the farm to inflation
The consequences do not necessarily stop at the market. Research by economists at the European Central Bank and the Potsdam Institute for Climate Impact Research, published in Communications Earth & Environment in 2024, examined how global warming and extreme heat can feed into inflation. Under projected 2035 conditions, the study estimates that annual food inflation could rise by 0.92–3.23 percentage points a year on average globally, depending on emissions scenarios, climate models and empirical specifications.
The researchers also estimate that Europe’s extreme summer heat of 2022 raised food inflation by 0.43–0.93 percentage points, and that warming projected for 2035 would amplify the effect of similar extremes by 30–50 per cent.
When food prices rise, people on lower incomes have less room to absorb the increase. The Environmental Research Letters study notes that households may respond by spending more of their income on food, buying less food or switching to cheaper and often less nutritious options.
What ends up on the plate?
The World Food Programme (WFP) estimated on 5 August that the 2026–27 El Niño could push at least 49 million more people into acute food insecurity by the end of 2027, across the 45 countries it assessed. Those are countries already considered food insecure and where El Niño is expected to have a significant effect. The number of acutely food-insecure people in them could rise from about 225 million to 274 million.
And as the climate warms, the concern is not simply whether a tomato or potato will disappear from the plate.
It is whether climate shocks will make food production more uncertain, prices more volatile and nutritious diets harder to afford.
A lone pedestrian walks through a light drizzle on a Kerala road as India records its driest southwest monsoon in 11 years. Representational image. Image credit: DoLiks/Pexels
India has ended the 2026 southwest monsoon with its lowest seasonal rainfall, driest monsoon in 11 years, with the country receiving 759.4 mm between June and September against a long-period average of 868.6 mm. The 12.6% deficit makes this the weakest monsoon since 2015 and the fourth-lowest since 2001, according to the India Meteorological Department (IMD).
The national figure, however, masks a much more uneven rainfall season. While some parts of the country received close to normal rainfall, large parts of eastern, northeastern and southern India experienced significant shortages.
Rainfall Shortfall Concentrated in Regions
The East and Northeast region recorded rainfall at about 74% of its long-period average, while South Peninsular India received about 76% of its average rainfall. The East and Northeast had their lowest southwest monsoon rainfall since 1901, while South Peninsular India recorded its second-lowest monsoon rainfall since 2001.
Of India’s 36 meteorological subdivisions, 17 recorded deficient rainfall, covering around 42% of the country’s geographical area. Another 18 subdivisions recorded normal rainfall. At the district level, 282 districts, or around 38% of the country’s districts, ended the season with deficient rainfall.
The uneven distribution matters because a national rainfall average does not translate into the same water availability everywhere. A district that receives normal rainfall cannot compensate for prolonged deficits in another region where agriculture, reservoirs or groundwater depend heavily on the monsoon.
Driest Monsoon: June’s Deficit Set the Tone
The shortfall was particularly pronounced at the beginning of the season. June rainfall was 35.4% below normal, followed by a 16.3% deficit in August and a 7.6% deficit in September. July was the exception, recording around 1% above normal rainfall.
The season also saw unusually frequent low-pressure systems. Fourteen such systems formed during the monsoon, producing 77 low-pressure-system days compared with the normal 57. According to IMD Director General Mrutyunjay Mohapatra, these systems helped prevent the seasonal deficit from becoming larger.
This uneven pattern is important for agriculture. A season can produce a near-normal rainfall total while still leaving crops exposed if rain arrives too late, falls in short intense spells or remains absent during critical stages of crop growth.
What does it Mean for Agriculture?
The immediate concern now shifts from kharif crops to the water conditions entering the rabi season. Lower rainfall can reduce soil moisture and leave rain-fed farming regions more dependent on stored water or irrigation. The impact will vary by crop and region rather than follow the national rainfall deficit directly.
The IMD had warned ahead of the monsoon that below-normal rainfall could create challenges for agriculture, water availability and hydropower, while increasing pressure on drinking-water resources.
Ripening paddy crops amid India’s driest monsoon in 11 years, with the 2026 southwest monsoon ending 12.6% below normal. Representational image. Image credit: Quang Nguyen Vinh/Pexels
The agricultural impact is already visible in some indicators. Kharif sowing stood at 110.8 million hectares as of September 25, about 1.2% below the previous year, while rice acreage was down 3.6%. Pulses, meanwhile, recorded an increase in acreage. The next concern is therefore not simply how much rain India received, but how much usable water remains available for farms, households and other sectors through the coming months.
El Niño Added Pressure
The weak monsoon developed alongside El Niño conditions in the tropical Pacific. The IMD had anticipated this risk before the season, forecasting in May that 2026 monsoon rainfall could be around 90% of the long-period average, with a model error of ±4%. It also gave a 60% probability of rainfall being in the deficient category.
By the end of the season, the IMD said El Niño conditions had strengthened and contributed to the rainfall deficit. The weather system is expected to persist into the coming months, although its influence on rainfall varies across regions and seasons.
The relationship between El Niño and the Indian monsoon is not absolute. Government data notes that, since 1950, there have been 16 El Niño years, of which seven were associated with below-normal Indian monsoon rainfall. The strength and timing of El Niño also influence its effect. The monsoon has ended, but the water story has not
The IMD expects October rainfall to remain below normal nationally, adding another layer of uncertainty after an already deficient southwest monsoon.
For India, the significance of the 2026 monsoon will therefore extend beyond the final 12.6% deficit. The more important questions are regional: which reservoirs have been replenished, where groundwater has taken a hit, how rain-fed farmers are entering the rabi season and whether drinking-water systems have enough buffer for a potentially drier post-monsoon period. The season is a reminder that rainfall totals alone cannot describe India’s water security. What matters on the ground is where the rain fell, when it fell and how much of it could be stored and used after the clouds cleared.