Editing Himalayas (section)

==Climate==
===Temperature===
The physical factors determining the climate in any location in the Himalayas include latitude, altitude, and the relative motion of the [[Southwest monsoon]].{{sfn|Zurick|Pacheco|2006|p=50}} From north to south, the mountains cover more than eight degrees of latitude, spanning temperate to subtropical zones.{{sfn|Zurick|Pacheco|2006|p=50}} The colder air of Central Asia is prevented from blowing down into South Asia by the physical configuration of the Himalayas.{{sfn|Zurick|Pacheco|2006|p=50}} This causes the tropical zone to extend farther north in South Asia than anywhere else in the world.{{sfn|Zurick|Pacheco|2006|p=50}} The evidence is unmistakable in the Brahmaputra valley as the warm air from the [[Bay of Bengal]] bottlenecks and rushes up past [[Namcha Barwa]], the eastern anchor of the Himalayas, and into southeastern Tibet.{{sfn|Zurick|Pacheco|2006|p=50}} Temperatures in the Himalayas cool by 2.0 degrees C (3.6 degrees F) for every {{convert|300|m|ft}} increase of altitude.{{sfn|Zurick|Pacheco|2006|p=50}}
[[File:Kowang, Gandaki River, Nepal.jpg|thumb|[[Gandaki River]] in Nepal]]
As the physical features of mountains are irregular, with broken jagged contours, there can be wide variations in temperature over short distances.{{sfn|Zurick|Pacheco|2006|pp=50–51}} Temperature at a location on a mountain depends on the season of the year, the bearing of the sun with respect to the face on which the location lies, and the [[mass versus weight|mass]] of the mountain, i.e. the amount of [[matter]] in the mountain.{{sfn|Zurick|Pacheco|2006|pp=50–51}} As the temperature is directly proportional to received radiation from the sun, the faces that receive more direct sunlight also have a greater heat buildup.{{sfn|Zurick|Pacheco|2006|pp=50–51}} In narrow valleys—lying between steep mountain faces—there can be dramatically different weather along their two margins.{{sfn|Zurick|Pacheco|2006|pp=50–51}} The side to the north with a mountain above facing south can have an extra month of the growing season.{{sfn|Zurick|Pacheco|2006|pp=50–51}} The mass of the mountain also influences the temperature, as it acts as a [[heat island]], in which more heat is absorbed and retained than the surroundings, and therefore influences the [[heat budget]] or the amount of heat needed to raise the temperature from the winter minimum to the summer maximum.{{sfn|Zurick|Pacheco|2006|pp=50–51}}

The immense scale of the Himalayas means that many summits can create their own weather, the temperature fluctuating from one summit to another, from one face to another, and all may be quite different from the weather in nearby plateaus or valleys.{{sfn|Zurick|Pacheco|2006|pp=50–51}}

===Precipitation===
The Himalayan hydroclimate is crucial for South Asia, where annual summer monsoon floods impact millions.<ref>{{cite journal |last1=Kad |first1=Pratik |last2=Ha |first2=Kyung-Ja |title=Recent Tangible Natural Variability of Monsoonal Orographic Rainfall in the Eastern Himalayas |journal=Journal of Geophysical Research: Atmospheres |publisher=AGU |language=en |doi=10.1029/2023JD038759 |date=27 November 2023|volume=128 |issue=22 |bibcode=2023JGRD..12838759K |doi-access=free }}</ref>

A critical influence on the Himalayan climate is the [[Southwest Monsoon]]. Variability in monsoon rainfall, influenced by local Hadley circulation and tropical sea surface temperatures, is the main factor behind wet and dry years.<ref>{{cite journal |last1=Kad |first1=Pratik |last2=Ha |first2=Kyung-Ja |title=Recent Tangible Natural Variability of Monsoonal Orographic Rainfall in the Eastern Himalayas |journal=Journal of Geophysical Research: Atmospheres |publisher=AGU |language=en |doi=10.1029/2023JD038759 |date=27 November 2023|volume=128 |issue=22 |bibcode=2023JGRD..12838759K |doi-access=free }}</ref> This is not so much the rain of the summer months as the wind that carries the rain.{{sfn|Zurick|Pacheco|2006|pp=50–51}} Different rates of heating and cooling between the Central Asian continent and the [[Indian Ocean]] create large differences in the [[atmospheric pressure]] prevailing above each.{{sfn|Zurick|Pacheco|2006|pp=50–51}} In the winter, a high-pressure system forms and remains suspended above Central Asia, forcing air to flow in the southerly direction over the Himalayas.{{sfn|Zurick|Pacheco|2006|pp=50–51}} But in Central Asia, as there is no substantial source for water to be diffused as vapour, the winter winds blowing across South Asia are dry.{{sfn|Zurick|Pacheco|2006|pp=50–51}} In the summer months, the Central Asian plateau heats up more than the ocean waters to its south. As a result, the air above it rises higher and higher, creating a [[thermal low]].{{sfn|Zurick|Pacheco|2006|pp=50–51}} Off-shore high-pressure systems in the Indian Ocean push the moist summer air inland toward the low-pressure system. When the moist air meets mountains, it rises and upon subsequent cooling, its moisture condenses and is released as rain, typically heavy rain.{{sfn|Zurick|Pacheco|2006|pp=50–51}} The wet summer monsoon winds cause precipitation in India and all along the layered southern slopes of the Himalayas. This forced lifting of air is called the [[orographic effect]].{{sfn|Zurick|Pacheco|2006|pp=50–51}}
[[File:Machermo, Yaks, Nepal.jpg|thumb|A caravan of [[yak]]s in the Himalayas]]

===Winds===
The vast size, huge altitude range, and complex topography of the Himalayas mean they experience a wide range of climates, from humid subtropical in the foothills, to cold and dry desert conditions on the Tibetan side of the range. For much of the Himalayas—in the areas to the south of the high mountains, the [[monsoon]] is the most characteristic feature of the climate and causes most of the precipitation, while the [[western disturbance]] brings winter precipitation, especially in the west. Heavy rain arrives on the southwest monsoon in June and persists until September. The monsoon can seriously impact transport and cause major landslides. It restricts tourism – the trekking and mountaineering season is limited to either before the monsoon in April/May or after the monsoon in October/November (autumn). In Nepal and Sikkim, there are often considered to be five seasons: summer, [[monsoon]], autumn, (or post-monsoon), winter, and spring.<ref>{{Cite web |title=Weather & Season Info of Nepal |url=https://classichimalaya.com/weather-season-info-of-nepal/ |access-date=2024-03-28 |website=Classic Himalaya |language=en-US}}</ref>

Using the [[Köppen climate classification]], the lower elevations of the Himalayas, reaching in mid-elevations in central Nepal (including the Kathmandu valley), are classified as ''Cwa'', [[humid subtropical climate#South Asia|Humid subtropical climate]] with dry winters. Higher up, most of the Himalayas have a [[Oceanic climate#Subtropical highland variety (Cfb, Cwb)|subtropical highland climate (''Cwb'')]].{{Citation needed|date=December 2023}}

The intensity of the southwest monsoon diminishes as it moves westward along the range, with as much as {{convert|2,030|mm|abbr=on}} of rainfall in the monsoon season in [[Darjeeling]] in the east, compared to only {{cvt|975|mm|abbr=on}} during the same period in Shimla in the west.<ref>{{cite encyclopedia|title=Climate of the Himalayas|url=https://www.britannica.com/place/Himalayas/Climate|access-date=18 May 2022|encyclopedia=Encyclopedia Britannica}}</ref><ref>{{citation|title=Illustrated Atlas of the Himalaya|first1=David|last1=Zurick|first2=Julsun|last2=Pocheco|publisher=University Press of Kentucky|date=2006|isbn=9780813173849|page=52}}</ref>

The northern side of the Himalayas, also known as the Tibetan Himalaya, is dry, cold, and generally windswept, particularly in the west where it has a [[Desert climate#Cold desert climates|cold desert climate]]. The vegetation is sparse and stunted and the winters are severely cold. Most of the precipitation in the region is in the form of snow during the late winter and spring months.

{{multiple image
| align             = right
| direction         = vertical
| image1            = View on Gyakar (edited).jpg
| caption1          = The [[Desert climate#Cold desert climate|cold desert]] region of [[Upper Mustang]]; the region lies to the north of the [[Annapurna (mountain range)|Annapurna massif]] (visible in the background)
| image2            = BhurjungKhola-AK1981.jpg
| caption2          = A village in the [[Pokhara Valley]] during the monsoon season; the valley lies to the south of the [[Annapurna (mountain range)|Annapurna massif]]
}}

Local impacts on climate are significant throughout the Himalayas. Temperatures fall by 0.2 to 1.2&nbsp;°C for every {{cvt|100|m|||abbr=}} rise in altitude.<ref>{{Cite journal|last1=Romshoo|first1=Shakil Ahmad|last2=Rafiq|first2=Mohammd|last3=Rashid|first3=Irfan|date=March 2018|title=Spatio-temporal variation of land surface temperature and temperature lapse rate over mountainous Kashmir Himalaya|url=http://link.springer.com/10.1007/s11629-017-4566-x|journal=Journal of Mountain Science|language=en|volume=15|issue=3|pages=563–576|doi=10.1007/s11629-017-4566-x|bibcode=2018JMouS..15..563R |s2cid=134568990|issn=1672-6316}}</ref> This gives rise to a variety of climates, from a nearly tropical climate in the foothills, to [[tundra]] and permanent snow and ice at higher elevations. Local climate is also affected by the topography: The leeward side of the mountains receive less rain while the well-exposed slopes get heavy rainfall and the [[rain shadow]] of large mountains can be significant, for example, leading to near desert conditions in the [[Upper Mustang]], which is sheltered from the monsoon rains by the [[Annapurna]] and [[Dhaulagiri]] massifs and has annual precipitation of around {{cvt|300|mm|||}}, while [[Pokhara]] on the southern side of the massifs has substantial rainfall ({{cvt|3900|mm|disp=or||}} a year). Thus, although annual precipitation is generally higher in the east than in the west, local variations are often more important.{{Citation needed|date=December 2023}}

The Himalayas have a profound effect on the climate of the [[Indian subcontinent]] and the Tibetan Plateau. They prevent frigid, dry winds from blowing south into the subcontinent, which keeps South Asia much warmer than corresponding [[temperate]] regions in the other continents. It also forms a barrier for the [[Monsoon of Indian subcontinent|monsoon]] winds, keeping them from traveling northwards, and causing heavy rainfall in the [[Terai]] region. The Himalayas are also believed to play an important part in the formation of Central Asian deserts, such as the [[Taklamakan]] and [[Gobi]].<ref>{{cite news|last=Devitt|first=Terry|title=Climate shift linked to rise of Himalayas, Tibetan Plateau|newspaper=University of Wisconsin–Madison News|date=3 May 2001|url=https://news.wisc.edu/climate-shift-linked-to-rise-of-himalayas-tibetan-plateau/|access-date=1 November 2011}}</ref>