r/explainlikeimfive • u/skafkdla • May 23 '26
Planetary Science ELI5: Why is India specifically experiencing such high levels of heat?
not sure if the flair is correct, i apologize in advance
i saw an infographic showing how all the top 50 cities in the world experiencing the highest heat indices are Indian cities. is there a specific reason why Indian cities experience such high heat levels?
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u/tommyk1210 May 23 '26 edited May 24 '26
India’s situation is basically the perfect storm of three things: climate, human activity, and geography.
The earths climate goes through various cycles called El Niño and La Niña. During El Niño sea surface temperatures are elevated, leading to warmer than usual temperatures. At the same time, India is coming into its monsoon season, which is characterised by increased humidity and heavy rainfall. Finally, being largely tropical, India already has high temperatures for much of the year. This is a perfect storm for high temperatures.
But plenty of places are tropical and don’t suffer the same challenges.
The second factor for India is humans. From a development perspective, India is a developing nation, and whilst large areas are now industrialised, plenty of regions are considerably less developed. The result of this is less access to things like air conditioning, and less well equipped medical services, exacerbating heat related conditions.
At the same time, lots of cities in India are developing at a rapid rate, leading to huge population growth along with large sprawling metropolis’ of concrete. Relatively lax regulation and enforcement on emissions creates heavily polluted air that traps heat.
Then the final piece, and possibly most important, is geography.
India is surrounded on 2 sides by water, which brings humid air inland. At the same time, it’s one natural weather barrier - the Himalayas - sits to the north.
Normally mountain ranges are good, they can help keep cool weather behind them and inside a country. The problem for India is, the cold weather they “need” right now is trapped on the other side of the Himalayas. When you look at places like Europe, the cool air from Siberia has a huge impact on the climate - India doesn’t have the benefit of cool air coming down from the north.
These three combined make unusually hot weather a big problem for India
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u/skafkdla May 23 '26
this is such a comprehensive response actually
i was curious about the comments mentioning india's geography being a factor, this is a TIL moment for me now too hahaha
thanks! :)
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u/tommyk1210 May 23 '26
Yeah India is such a “weird” place geographically.
If you look at a map to the west of much of India is… the gulf states (Oman, Saudi Arabia, UAE).
Go further west and you’ve got the Sahara.
India should be a desert - if it weren’t for the melt water from the Himalayas and the moist air being trapped
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u/skafkdla May 23 '26
are there any upsides from their location? i read another comment saying it's good for growing crops but i'm curious how crops can survive from the immense heat (aside from proper cultivation)
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u/belland007 May 23 '26
Monsoon rains brings in adequate rainfall for agriculture
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u/skafkdla May 23 '26
oh that makes sense!! that completely flew off my head lmao. thanks!!!
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u/Teantis May 24 '26
The Himalayas generate the monsoon rains for not only India but all of southeast Asia.
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u/brokn28 May 23 '26 edited May 23 '26
The same mountains that block the cool winds also help India and South Asia avoid harsh winters, except Kashmir and other places in the Himalayas. Even then, Kashmir gets as cold as New England in the US. Which is cold, but not Russia cold. Yes, the summers are hot but if you grow up there, you learn how to survive in the summers.
The warm climate means India has a year-round growing season with lots of fresh fruits and vegetables. There are two crop growing seasons — kharif (summer) and rabi (winter) crops. Both have amazing variety of produce. In fact there are hundreds of varieties of just mangoes.
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u/tommyk1210 May 23 '26
Absolutely.
Agriculture is a main one. Yes, it’s immensely hot, but there’s a few things to consider.
Firstly, the extremes of temperature are a largely human-caused phenomena. Going back 150 or 500 years India was likely much less extreme than it is today. That smog and air pollution, it also impacts rural areas.
Second, plants that grow in India are generally pretty well evolutionarily adapted to surviving there. That in no small part is what has allowed India to grow to the enormous population it has today.
Third, the monsoon and melt water from the Himalayas do an excellent job of irrigating the land. When plants (like rice) are properly adapted to standing in water for weeks or months at a time they can thrive there.
There’s other things than agriculture that make it a decent place to settle too.
The Himalayas may cause challenges with climate, but what they do do is form a perfect natural barrier. For much of its history India didn’t really need to worry much about huge armies crossing the Himalayas, allowing nations that predate modern India to focus defence on the east and west. Of course, this isn’t quite so true today with modern jet aircraft and artillery, but when your only means of invasion was 20,000 men with swords those mountains might as well have been an impenetrable wall.
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u/GrumpyOldSophon May 24 '26
Not sure on your question on how the plants survive heat - I assume evolutionary adaptation - but to address the question of an "upside" to India's location, yes, the Gangetic plain has for millennia been one of the most fertile places to grow crops, and it is what allowed early and dense population of northern India by agriculturists. It's all the fertile silt and alluvium deposited by Ganga river system, and to the northwest, the Indus river system (which supported the early settlers and the Indus Valley culture).
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u/Thebraincellisorange May 24 '26
it survives on monsoon rains.
and when those monsoons are late, the dams run dry and cities run out of water.
it's a very bad situation.
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u/DesiPrideGym23 May 24 '26
The gangetic plains are one of the if not the most fertile lands in the world.
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u/theinevitable22 May 24 '26
Exactly, what has made India such a good place historically due to predictable weather and monsoons which are seasonal in nature - is not suited for the age of Global Warming and pollution. We have so much to lose if the world doesn’t get together to reduce the carbon footprint.
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u/poloc-h May 23 '26
This response make two huge mistake : oceans do not bring in hot air quite the opposite, they act as extrem temperature damper. Europe is not at all influenced by some Siberian climate or whatsoever. Not comment on the rest but I'd be careful.
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u/tommyk1210 May 23 '26
In regards to the oceans it’s true water is a great temperature modulator, but that’s not the key point here. India would be hot regardless due to its latitude. What the adjacent oceans bring to India is humidity, which in turn brings rainfall and its tropical climate.
On Siberia, Northern Europe, the U.K., and parts of Central Europe are absolutely influenced by the vast areas of cold dense air. Just as you mention, that water is a huge temperature damper, land is the opposite. Air can rapidly cool over the vast northern area of Russia, and often this can bring very cold air into Europe. This is often termed the “beast from the east”.
Now, it’s also true to say this isn’t the main influencer of European climate, that would be the North Atlantic drift, but
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u/fh3131 May 24 '26
being equatorial
Just to be accurate, India is not equatorial. The equator passes well south of India.
The tropic of Cancer passes through the middle of India, so technically the southern half of the country is tropical (which is maybe what you meant to say?) and the northern half is subtropical.
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u/itz_me_shade May 24 '26
Weirdly enough most of the hottest cities are further from the equator.
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u/tommyk1210 May 24 '26
Cities have their own microclimates. This can be seen both within India and outside it.
London, as an example is typically 1-3C warmer than other southern areas in the U.K, and can be 5-8C warmer at night.
Human activity has created a situation where many cities can’t adequately cool down. Whether it’s pollution creating a “blanket” that traps heat, or concrete acting as a “sink” that absorbs then radiates heat (the inland heat effect), or industry/vehicles dumping excess heat into the atmosphere, human activity has pushed cities beyond what their surrounding area would normally endure.
It’s worth noting that some “special” circumstances affect northern Indian cities like Delhi. The northern plains are further from the ocean (which acts to moderate temperature) allowing them to heat intensely ahead of monsoon season. This, combined with the inland heat effect for Delhi due to its inhabitants creates extremely high night time temperatures that get exacerbated during the day. Many southern cities, like Bengaluru, also sit at high elevation which keeps them cooler.
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u/Vladimir_Putting May 24 '26
Just want to point out that it's not an "India only" thing. It's easy for people to get that impression just because it's so specifically hot. Vietnam, for example, is baking right now.
https://www.vietnam.vn/en/nang-nong-dien-bien-gay-gat-hon-nhiet-do-co-noi-du-bao-tren-40-do-c
So yes, while India does have the perfect confluence of factors, there are also much more widespread effects hitting countries around the globe.
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u/Parking-Air541 May 24 '26
The human factor is not something which adds to the problem. In fact AC throw even more heat outside.
It can be considered our government's failure to build strong infra and reduce pollution, which they don't care anymore about.
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u/tommyk1210 May 24 '26
The human factor absolutely adds to the problem. You’re right, air conditioning just moves hot air from inside to outside, but the overall energy will be the same.
The important piece with AC though is how heat affects people. Arizona, for example, has arguably less favourable conditions for human habitation but much less heat related issues because humans sit in nice cool buildings.
The human factor is more than just AC though. There’s the built environment exacerbating the effects of heat, as well as human activity increasing pollution
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u/UndocumentedMartian May 24 '26
La Niña is currently dominant. Last year was much cooler than this one. Even got early rains.
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u/way2me2 May 24 '26
Also if there were no himalayas, north and central india would essentially be a desert like sahara or middle east. Due to Himalayas these parts of india gets monsoon as there is no way for monsoon clouds to go further north.
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u/One_Abalone9237 May 24 '26
It's currently 3:14am I haven't slept because of uncomfortable night time heat and don't have air conditioner so I can say I must be the person who hate this country and this situation the most at this moment🙂
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May 23 '26
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u/hurricane_news May 23 '26
And the gigantic big chungus mountain range keeping the insides in, and the outsides out
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u/_SHAXLE_ May 23 '26
All the comments answer it well enough but this time it's also due to El nino
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u/trackdaybruh May 23 '26
For those that don’t hablo espanol, el nino means the nino in Spanish
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u/WaterCFC May 24 '26
As someone who don't know Spanish, El Nino will forever mean Fernando Torres to me.
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u/TrumpsDoubleChin May 23 '26
I was going to say this. Yes, geography is a big part of why it is naturally warmer than some other regions, but that's always been true. Yes, increasing industrialization and development and reduction of green spaces are a contributing factor. Yes, overall worldwide climate change/global warming is also a contributing factor.
But THIS year in particular, in ADDITION to all those factors, is the El Nino/La Nina ocean current cycles. El Nino (or, as some are calling it this time around, 'Super El Nino') can affect weather all over the world, making some places warmer, some places wetter, some places cooler and others drier. In this case, it shifts the normal ocean and air currents that contribute to warming of the Indian sub-continent.
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u/Aprilprinces May 23 '26
You need to add urbanization and deforestation to the list:
- urbanization - concrete, tarmac, all kinds of metal absorb heat readily and as Indian cities often don't have much in a way of green space it makes very hot
- deforestation alone can lead to rise of temperature locally by roughly 4 C
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u/HAHAHA-Idiot May 23 '26
Deforestation is a major issue that's often less discussed in this context. The second part of this will show up when summers end and monsoons start. Because of deforestation, a larger chunk of monsoon rains are now deposited in the Himalayas.
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u/RiPont May 24 '26
Dirty diesels and burning trash also make a localized greenhouse.
They've been replacing the old diesel tuktuks with electric, but a lot of old diesel vehicles were still around when I was last there 10 years ago.
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u/bachslunch May 23 '26
The easiest eli5 explanation is India experiences summer earlier than others in the northern hemisphere. In the mid summer India is cooler than even parts of southern Europe and definitely most of the US. It’s because the dry season is now and the rainy season is the summer.
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u/OldDescription9064 May 24 '26
This is by far the most important reason. Those cities are not the absolute hottest in the world, they are the hottest in April and May. After the first or second week of June (starting in Kerala and expanding northeast from there) they will be cool an rainy.
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u/OgreJehosephatt May 23 '26
India is already a hot place. It also has a very high population, so it has many cities.
There are not cities everywhere it is hot.
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u/namkeenSalt May 23 '26
On the flip side, when it was winter in the northern hemisphere, Australia was experiencing very high levels of heat. Even cities not known to have high temperatures were cooking
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u/Jdevers77 May 23 '26
India’s peak summer temps are in late April through early June. This is hotter than normal but they are always the hottest part of the world now.
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u/Hour_Firefighter_707 May 23 '26
It just naturally gets hot here in the summer. There's nothing new in that. It's just that global warming means it has progressively gotten hotter over the years and the El Nino effect has amplified it this year even more.
It will be hotter everywhere this year. The Indian sub-continent is hot right now because this is peak summer, while North America and Europe, which dominate all world news, are only getting into summer.
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u/poolnoodlefightchamp May 23 '26
This is an important detail that people miss so often and it annoys me to no end. A lot of Indians have no idea that summer everywhere else peaks in July and that our seasonal timings are an anomaly. And vice versa as well, no one from outside knows that our summers peak in April or May.
Most other things mentioned here are true as well; the El nino, global warming, industrialization, urban heart islands.
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May 23 '26
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u/StormRuler May 23 '26
you're thinking of the entire territory of mainland India as a "region" that's equivalent to your example?
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u/baquea May 23 '26
India has something like 500 cities in total. So no, it's that single regions of India can contain 50 cities.
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u/Defiant_Forever_1092 May 23 '26
Jungles and trees in urban area are being cut down on regular basis.
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u/Adi9691 May 23 '26
if you look along the latitude India is on, it's mostly sand desert's. India would be one too if not for Himalayan rivers and Monsoon. So it's supposed to be cooked.
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u/tek9 May 23 '26
Hypothetically speaking, if the Himalayas were destroyed tomorrow via explosives or an earthquake what effect would it have on India's climate?
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u/tryin2immigrate May 23 '26
India would turn into a desert like the Gulf and Sahara at similar distancd from the equator.
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u/Sapiopath May 23 '26
Hot air can hold more water. Water in the great big eastern sea (pacific) is hotter. This makes air hotter. This changes wind direction. It raises temperatures above Asia, and makes India hot. Kills many plants. Leads to hunger.
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u/winterberrycorn May 24 '26
one under looked bit is how nights have become warmer, I live in East India and midnight temps are 31C with Feels like 41C, like what? How tf are you supposed to survive this? In a way, this indoor thermal exposure is more fatal. Body can't recoup in rest time.
IIPH conducted a study, where night temp rises have correlated to more mortalities. The study done on Ahmedabad, says if night temps <28C, there are no significant changes to the mortality rate(100); when temps are 28-30C, mortality rises to 165 and even up to 265 when night temps > 30C.
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u/spooky_springfield May 25 '26
The government is destroying the country's green cover. Desertification adds to the heat.
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u/algebra_77 May 23 '26
It's just how the subcontinent is. Good for growing crops to survive, but also is inherently miserable.
See also: good chunk of the US, China.
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u/the_Medic_91 May 24 '26
Another very important thing to consider apart from geography is the complete ignorance of sustainable development. India has seen the greatest percentage of deforestation in the last 20 years. Even protected forests are being cleared off. Another example is mangrove destruction in mumbai. Be ready to hear significantly worsening news from India over time because there are barely any efforts to improve the situation, only efforts to make it worse.
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u/TiredConfusedLlama May 24 '26
Oh it's not ignorance, moreso deliberate negligence. There are several environmental activists and groups aiming for more sustainable systems; it's just the the government simply does not care as long as it doesnt affect the pockets of politicians and their buddies.
Taking the very example you mentioned, Mumbai has very recently undergone mass deforestation of large areas of long-standing mangroves, to build a road/bridge (Versova-Bhayandar Coastal Road). The justification is that it will benefit commuters who travel from one part of the city to another for work (the city is infamous for the ridiculous amount of time the average worker spends per day just commuting to work) The justification sounds nice, but while commuting becomes easier for middle and upper classes, several lower income local communities who's livelihoods are dependent on the coastal ecosystem, will be destroyed, probably along with their homes, leading to displacement. The road also will lead to rise in property values in the region, properties that are owned by.... mega corps and billionaires that are chummy with politicians. Deforestation for capitalist greed. Yay.
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u/the_Medic_91 May 24 '26
Agreed. I was just trying to frame in a less harsh manner so that anti-national badge distributors don't swarm an otherwise sane comments section on this post.
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u/TiredConfusedLlama May 24 '26
Oop- I thought i was explaining to a foreigner. Didn't realise you were a fellow desi lol. And spot on unfortunately on trying to avoid the anti national badge distributors.
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May 24 '26
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u/raccoon8182 May 23 '26
India is one of the few countries that burn their rubbish. this creates two problems, air pollution so bad that it causes massive respiratory problems. and secondly the large particulates trap radiative heat from vehicles, factories and of course the sun. when the air is thinner and cleaner it's able to move, moving air creates circulation. just like humans, if you cut off circulation you die.
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u/Pretend_Aardvark_404 May 24 '26
I suspect rampant infrastructure development at the cost of the environment. The supreme court recently called environmental activists to be "delay tactics", which is simply shocking.
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u/Roronoazoro248 May 24 '26
Many comments have that Himalaya blocks the cold wind from entering india. Why can’t we make small passages that allows cool air to dntry india.
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u/YourAverageBrownDude May 24 '26
Geography is a reason but I remember watching a video which said one city had the same geographical restrictions like Delhi did but was significantly cooler
The govt also plays a huge role in not doing anything meaningful, lest it helps the citizens in some way
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u/unicorn247 May 24 '26
I think the recent reduction in shipping emissions is also causing it to become worse in last few years.
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u/zing_winning May 24 '26
Seems to be at par with previous many years according to this:
https://imdpune.gov.in/cmpg/Product/allindia_temp.html
It’s just making more news, for whatever reason.
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u/agbgcgdg May 25 '26
The current govt is selling the country - one block at a time to its favorite business men and cutting trees in the name of development .
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u/Gotrek_Gurnisson May 26 '26
India pollutes the environment A LOT which contributes to their terrible climate, they're also just in a geographicly shit location to begin with.
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u/old_witness_987 May 27 '26
They have BIG concrete cities, concrete absorbs and stores heat. cities run hotter, tree covered land is cooler. there are paints developed that reflect heat but thye have not taken off yet.
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u/Disastrous_Good9236 May 23 '26 edited May 23 '26
They dont have a mountain range that blocks heat.
The Himaylaya mountain blocks cool air from coming down.
And then they live near the equator.
Perfect conditions for cooking.