Environment and Disaster Management › Climate science
हिन्दी — Read in HindiExtreme weather, monsoon and forecasting
Weather and its extremes, the monsoon and the ocean patterns that drive it, heatwaves, cyclones, cloudbursts and lightning, and the forecasts and radars that meet them. Prelims has asked about the Finance Commission's recommendations on disaster funding.
Foundation note: Disasters: the notified calamities and the warning chain
All 8 articles shown; the 2 that changed from 1 to 31 July 2026 are marked.Show only these
Mission Mausam
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Mission Mausam is the Ministry of Earth Sciences programme, launched in 2024, to widen India's observing network, sharpen its models and take up weather modification research.
- Phase one built most of the network the country now warns from.
- A second phase runs from 2026 to 2031 through six verticals, of which weather modification is one.
- Its targets are set for 2030: forecasts 10 to 15 per cent more accurate, and hazard forecasts on a 5 km grid reaching every household.
- The Bharat Forecast System is the model at its centre.
The Doppler radar and the hills
- A Doppler weather radar sends out a microwave pulse and reads the echo from raindrops, snow and hail, which tells it where precipitation is and how heavy.
- The Doppler shift in that echo gives the speed at which the drops move, so the radar reads the wind inside a cloud.
- Scanning every few minutes, it follows a storm as it builds, which is what turns a forecast into a warning.
- In the hills a ridge blocks the beam and the valley behind goes unwatched, while a radar placed high enough to see over ridges passes above the low cloud dropping the rain.
- A cloudburst builds and empties within the hour, so a gap in cover is a warning that never comes.
What changed
22 Jul 2026
- The Bharat Forecast System now runs operationally at a horizontal resolution of 6 km, against about 12 km for the older global model.
- It issues forecasts for a cluster of panchayats rather than a district.
- Warnings travel as Common Alerting Protocol alerts through the SACHET app.
PIB, 22 Jul 2026: PARLIAMENT QUESTION: BHARAT FORECAST SYSTEM (opens in a new tab) · PIB, 22 Jul 2026: PARLIAMENT QUESTION: IMPLEMENTATION OF MISSION MAUSAM (opens in a new tab) · PIB, 23 Jul 2026: PARLIAMENT QUESTION: IMPLEMENTATION OF MISSION MAUSAM (opens in a new tab)
Show history (1 other update)
5 Jun 2026BriefIMD's seventh Regional Meteorological Centre opened at Jammu for Jammu and Kashmir, Ladakh and Himachal Pradesh, and Lucknow followed for Uttar Pradesh and Uttarakhand. Doppler radars rose from 17 in 2014 to 50, with about 100 planned within two years. PIB, 5 Jun 2026: Dr. Jitendra Singh Launches India's Seventh Regional Meteorological Centre in Jammu (opens in a new tab) · PIB, 8 Jun 2026: UP CM Yogi Adityanath and Union Minister Dr Jitendra Singh jointly Launch New Regional Meteorological Centre at Lucknow (opens in a new tab)
Background reading: Ministry of Earth Sciences, 5 Aug 2026: Mission Mausam: aims, phases and strategy (opens in a new tab)
The 2026 monsoon and El Niño
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LeadA dry monsoon under a strong El NiñoSeptember 2026
Why in news
The southwest monsoon ended on 30 September 2026 at 87 per cent of the long period average, the driest season in 11 years, and Maharashtra declared drought in 265 of its 358 talukas on 26 September.
- 87 per centof the long period average: 759.4 mm against 868.6 mm
- 13thdriest monsoon since 1901
- 282districts deficient, over 38 per cent of the country's area
- 265 of 358talukas of Maharashtra declared drought hit
Background
- The long period average (LPA) is the average monsoon rainfall over 1971 to 2020, and a season counts as normal when it falls between 96 and 104 per cent of it.
- El Niño is the abnormal warming of the surface waters of the equatorial Pacific, which suppresses Indian rainfall, while La Niña favours it.
- El Niño is declared on the Niño 3.4 index, the sea surface temperature anomaly in the central and eastern equatorial Pacific, which stood at +2.51°C.
Why the season was uneven
- Low pressure systems from the Bay of Bengal were active on 77 days against a normal 57, which kept central India wet despite El Niño.
- The Madden Julian Oscillation (MJO), a band of rain bearing clouds with a period of 30 to 60 days, stayed unfavourable over the south, so every southern State ended in deficit.
- Inside Maharashtra the deficit was 18 per cent, but Marathwada was 38 per cent short and Vidarbha 27 per cent, both rain shadow regions.
Drought and flood in the same season
- Odisha ended with a 29 per cent excess, brought by 11 Bay of Bengal systems one after another, which left the soil saturated and turned each new spell into runoff.
- A deep depression meeting a Western Disturbance flooded Uttar Pradesh in the last week of September, as the monsoon was withdrawing.
What lies ahead
- The India Meteorological Department (IMD) projects El Niño effects until at least March 2027.
- A strong El Niño generally favours a wetter northeast monsoon over the southern peninsula, though not in every such year.
- Long duration arhar flowers in October and fills its pods in November, so a dry spell then causes terminal moisture stress, and low soil moisture may hold back rabi sowing.
The way forward
- Build drainage for repeated intense downpours, since one day and five day rain bursts are becoming more common even as heavy rain days decline.
- Act on the forecast in crop planning: short duration pulses, millets and oilseeds where the season is expected to fail.
- Document the ecological effects of this El Niño, as 188 Indian scientists have asked, since a coral reef needs about a decade to recover from bleaching.
Prelims facts
- The LPA is calculated over 1971 to 2020; normal is 96 to 104 per cent of it.
- A Western Disturbance is an east moving extra tropical cyclone that gathers moisture from the Mediterranean, Black, Caspian and Arabian Seas and is carried by the subtropical westerly jet stream.
- The Indian Ocean Dipole can dampen or amplify El Niño's effect on India.
- The MJO moves with a period of 30 to 60 days.
El Niño is the warm phase of the equatorial Pacific and is usually, though not always, linked to a weaker Indian monsoon.
- Events are graded weak, moderate, strong or very strong; neither the World Meteorological Organization nor the India Meteorological Department recognises a "Super El Niño" category.
- The phase of the El Niño Southern Oscillation (ENSO) is set by the sea surface temperature anomaly over the Niño 3.4 region of the equatorial Pacific.
- Above +0.5°C is El Niño and below −0.5°C is La Niña, and episodes usually peak in the northern winter.
- A positive Indian Ocean Dipole can offset El Niño.
- The Department has used a Multi Model Ensemble of coupled models for its seasonal forecast since 2021.
What changed
30 Sep 2026LeadA dry monsoon under a strong El Niño
Monsoon floods of July 2026
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LeadThe floods of July 2026: cloudbursts, embankments and warningJuly 2026
Why in news
Assam's eastern districts saw what the State called its worst floods in 60 years in July 2026, after a cloudburst in Nagaland. In the same month floods struck Jammu and Kashmir, Gujarat and Odisha, each from a different cause.
Background
- A flood is not one hazard. A river flood builds over days; a flash flood arrives within hours of intense rain; an urban flood comes when drains cannot carry the water.
- A cloudburst is very heavy rain over a small area in a short time, common where moist air is forced up steep slopes.
- An embankment is a raised bank built along a river to hold it in its channel. It protects the land behind it only as long as the river keeps its course.
- The Brahmaputra carries a heavy load of silt, and it shifts its channels once it leaves the hills and enters the flat Assam valley.
Four floods, four causes
- Assam: a cloudburst in Nagaland's Mon district sent water down into Sivasagar, Charaideo, Jorhat and Golaghat, districts that rarely flood on this scale. It spilled over the embankments and ran across open country.
- Jammu and Kashmir: cloudbursts flooded Pahalgam, where hotels were criticised for standing on flood channels.
- Gujarat: a low pressure system from the Bay of Bengal met a western disturbance; the heavy spell flooded Navsari and Valsad in the south and closed highways in the Ahmedabad industrial belt.
- Odisha: a deep depression arrived at the end of a month that had already brought about twice the normal rain.
Why embankments were not enough
- The Assam flood did not come along the river's usual flood plain, so the embankments were in the wrong place.
- An embankment also raises the river bed over time, as silt settles inside it, and a breach then does more damage.
- Flood plain zoning, which regulates what may be built on land that floods, limits damage through land use and not through walls.
Warning: the landslide lesson
- About 13 per cent of India's land is prone to landslides.
- A fortnight before the Wayanad disaster of 2024, landslides in the Munnar hills caused no deaths, because the district evacuated people on the advice of a team testing a warning system.
- Such systems exist only as scattered pilots, not as a national network tied to an evacuation plan.
- The Bharat Forecast System now gives forecasts for a cluster of panchayats, which makes local warning possible.
The way forward
- Adopt flood plain zoning in State law, which most States have not done.
- Treat the river as a basin, across State lines, since Assam's flood began in Nagaland.
- Build warning into a national network with a fixed evacuation protocol, for landslides as for floods.
- Keep construction off flood channels and unstable slopes in hill towns.
Prelims facts
- Mon is a district of Nagaland; the flood it caused was in Upper Assam.
- About 13 per cent of India's land is prone to landslides.
- A deep depression ranks between a depression and a cyclonic storm.
- Flood control is largely a State subject.
This subject holds the floods of July 2026 in Assam, Jammu and Kashmir, Gujarat and Odisha, each set off by a different mechanism: a cloudburst upstream, cloudbursts in a valley, a heavy local spell and a deep depression.
What changed
Landslide early warning
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About 13 per cent of India's land, roughly 0.42 million sq km, is prone to landslides, and warning systems for them exist as scattered pilots rather than as a national network tied to an evacuation protocol.
See also: Glacial lake risk in India
Monsoon onset over Kerala
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Monsoon onset over Kerala is the monsoon's arrival over Kerala, declared by the India Meteorological Department only after 10 May and only when three tests are met.
- Rain: at least 60 per cent of 14 designated stations in Kerala, Lakshadweep and coastal Karnataka record 2.5 mm or more of rain on two consecutive days.
- Wind: westerly winds extend to about 4.5 km (600 hPa) over the southeast Arabian Sea at 15 to 20 knots.
- Cloud: outgoing longwave radiation (OLR) falls below 200 W/m² over 5 to 10°N, 70 to 75°E, a sign of deep cloud.
- The tests rule out a false pre monsoon onset.
- The monsoon then advances north in surges and normally covers the country by mid July.
- Onset date has little bearing on total seasonal rain.
How IMD declares onset
After 10 May
No declaration is made before this date
Rain
At least 60 per cent of 14 stations record 2.5 mm or more on two consecutive days
Wind
Westerlies extend to about 4.5 km over the southeast Arabian Sea
Cloud
Outgoing longwave radiation falls below 200 W/m²
Onset declared
The monsoon has set in over Kerala
What changed
4 Jun 2026New
- The India Meteorological Department (IMD) declared onset over Kerala on 4 June, three days after the normal date of 1 June and five days past the upper bound of its own forecast of 26 May plus or minus four days.
- It is the first miss beyond the error margin since 2015; the forecast was otherwise right every year from 2005 to 2025.
The Hindu, 4 Jun 2026: Monsoon sets in over Kerala three days late amid concerns over El Nino impact (opens in a new tab) · The Indian Express, 4 Jun 2026: Southwest monsoon hits Kerala, IMD forecasts heavy rainfall until June 7 (opens in a new tab)
See also: The 2026 monsoon and El Niño
Heat stress in India
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LeadHeat stress in India, and the cooling paradoxJune 2026
Why in news
Studies published in June 2026 found that humid heat is spreading in India beyond the summer into the monsoon, and that India has more cities among the world's most heat vulnerable than any other country. India's peak power demand reached a record in May, much of it for cooling.
Background
- Heat stress is the net heat load on the body. It depends on temperature, humidity, wind and radiation, and not on temperature alone.
- The body cools itself by sweating. When the air is humid, sweat does not evaporate and the cooling fails.
- A heatwave is declared by the India Meteorological Department on temperature. Humid heat can be dangerous at temperatures well below that threshold.
- Heat risk has three parts: exposure to the hazard, the vulnerability of the people exposed, and their capacity to cope.
What the studies found
- Uncompensable heat stress, in which the body cannot cool itself at all, now affects about 8 per cent of India in summer.
- At 2°C of global warming it could affect more than half the country, in the monsoon as well as the summer.
- The northwest and the Gangetic plain will see humid heat in the monsoon months.
- Fourteen Indian cities are among the world's fifty most heat vulnerable; Ahmedabad is second.
- Across the world the warmest nights are warming faster than the warmest days, which denies the body its recovery.
Who is most exposed
- Outdoor workers, and people in slum housing without ventilation, power or water.
- Children: a United Nations Children's Fund report gives India the highest score for children's exposure to extreme heat.
The cooling paradox
- Cooling protects people from heat, but air conditioners draw fossil power and use hydrofluorocarbons (HFCs), gases with a high global warming potential.
- So cooling a room warms the planet, and the city outside the room.
- Under the Kigali Amendment to the Montreal Protocol, India freezes its HFC consumption in 2028 and cuts it in phases until 2047.
- The India Cooling Action Plan of 2019 aims to cut cooling demand and refrigerant demand over two decades.
The way forward
- Put passive cooling first: cool roofs, shade, ventilation and building design.
- Make efficient appliances and low warming refrigerants the default.
- Extend Heat Action Plans to cover humid heat and warm nights, and not only daytime temperature.
- Protect outdoor workers through changed working hours, water and shade.
Prelims facts
- The Kigali Amendment is to the Montreal Protocol, and deals with HFCs.
- HFCs do not deplete ozone but have high global warming potential.
- India freezes HFC consumption in 2028.
- The India Cooling Action Plan dates from 2019.
Heat risk is not temperature alone: it depends on humidity, radiant heat and wind, and on who is exposed and how they can cope. Summer heat stress concentrates in the Indo Gangetic plain and the coasts, driven by high temperatures and pre monsoon moisture from the Bay of Bengal. Monsoon heat stress is humid, arriving at moderate temperatures of 35 to 38°C when humidity is high, especially during monsoon breaks. An Oxford study of 205 cities over a million people placed 14 Indian cities in the global top 50 for heat vulnerability, more than any country, Ahmedabad second and Nagpur fourth, scoring hazard, vulnerability and coping capacity.
- Mains: Passive cooling and low energy fans should be the first line of heat adaptation, since dependence on air conditioning raises power demand, refrigerant leaks and waste heat that warm the city further.
1970s versus now
| 1970s | Now | |
|---|---|---|
| People with at least 90 days of strong heat stress | 55 per cent | 70 per cent |
| People with at least one day of extreme heat stress | 16 per cent | 22 per cent |
What changed
23 Jun 2026LeadHeat stress in India, and the cooling paradox
See also: Heat Action Plans · Cooling and the Kigali Amendment
Drought declaration
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India has no single definition of drought, and it is the State government that declares one.
- To draw central funds, a State's report must follow the norms of the National Disaster Response Fund.
- The norms look at rainfall deficit, the moisture adequacy index, crop loss, sowing below half the usual area, falling groundwater, and shortage of drinking water and fodder.
- A central team verifies the report before money is released.
How drought is declared and funded
Rainfall deficit and dry spell
Trigger-1
Panchnamas by Collectors
State report to NDRF norms
Central team verifies
Funds released
What changed
29 Sep 2026New
- Maharashtra declared drought on 26 September in 265 of 358 talukas under its Drought Management Code, 2016.
- The Code's first alert stage, Trigger-1, rests on rainfall deficiency and a dry spell of at least 21 days.
- Collectors then begin panchnamas, field surveys of crop condition, and compensation for crop loss follows these surveys.
The Hindu, 29 Sep 2026: Why has Maharashtra declared drought in 265 talukas and what do farmers get? | Explained (opens in a new tab) · The Indian Express, 23 Sep 2026: Maharashtra is parched, but here's why drought can't be declared before October (opens in a new tab)
Swell surge
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A swell surge is coastal flooding caused by ocean swell that was generated far away, by a distant storm or a long gale.
- The swell usually forms in the southern Indian Ocean, travels thousands of kilometres and reaches the coast in two or three days.
- Fishermen in Kerala call it kallakadal.
- The Indian National Centre for Ocean Information Services (INCOIS) issues the alerts, and southern Kerala and Kanyakumari are hit first.
What changed
28 Sep 2026New
- INCOIS issued a red alert for Kerala and southern Tamil Nadu.
- Such alerts usually come before the monsoon, but this year El Niño kept monsoon seas calm, so distant swell stood out.
Also filed elsewhere
- Forest fires · on Forests, grasslands and mountain ecosystems
Forest fires in India are tracked through alerts that the Forest Survey of India (FSI) reads off satellite passes.
- Heat Action Plans · on India's climate policy: NDCs, net zero and adaptation
Extreme heat is met city by city rather than nationally, which is at once the strength of the instrument and its limit.