climate of the Alps
{{Short description|none}}
File:Altitudinal zones of Alps mountains-extended diagram.svg
The climate of the Alps is the climate, or average weather conditions over a long period of time, of the exact middle Alpine region of Europe.{{Cite book|title=Climate change in the European alps : adapting winter tourism and natural hazards management|last=Agrawala, Shardul.|date=2007|publisher=OECD, Organisation for economic co-operation and development|isbn=978-9264031685|oclc=729351518}}{{Cite journal|last1=Elsasser|first1=H|last2=Bürki|first2=R|date=2002|title=Climate change as a threat to tourism in the Alps|url=https://www.int-res.com/abstracts/cr/v20/n3/p253-257/|journal=Climate Research|language=en|volume=20|issue=3|pages=253–257|doi=10.3354/cr020253|issn=0936-577X|doi-access=free}} As air rises from sea level to the upper regions of the atmosphere the temperature decreases. The effect of mountain topography on prevailing winds is to force warm air from the lower region into an upper zone where it expands in volume at the cost of a proportionate loss of heat, often accompanied by the precipitation of moisture in the form of snow, rain or hail.
Climate as a function of elevation
{{see also|Life zones of central Europe|Lapse rate}}
Because air cools as it rises, the climate of the Alps is strongly dependent on the elevation. The Alps contain a number of different kinds of climate zones, by elevation. These zones can be described by the Köppen climate classification, and also correspond to the biotic zones of the Alps.{{cite journal|journal=Meteorologische Zeitschrift|volume=26|number=2|pages=115–125|date=January 24, 2017|title=The climate of the European Alps: Shift of very high resolution Köppen-Geiger climate zones 1800–2100|first1=Franz|last1=Rubel|first2=Katharina|last2=Brugger|first3=Klaus|last3=Haslinger|first4=Ingeborg|last4=Auer|doi=10.1127/metz/2016/0816 |doi-access=free}}
Up to approximately {{convert|1050|m|ft}} of elevation, the climate is classified as oceanic or Cfb under the Köppen system. Like much of lowland northern Europe, the summers are mild and the winters are cool, but not cold. The climate is moderated by proximity to the Atlantic Ocean. The climate creates the colline biotic zone in the lowlands, which is characterized by the deciduous forest of the Western European broadleaf forests ecoregion.
{{Weather box
|location = Buchs/Aarau (1991–2020), at {{convert|387|m|ft}}, {{Coord|47.38|N|8.08|E|region:CH-AG_type:landmark|name=Buchs, Aargau}}
|collapsed = yes
|metric first = Yes
|single line = Yes
| Jan high C = 3.9
| Feb high C = 5.9
| Mar high C = 11.1
| Apr high C = 15.6
| May high C = 19.6
| Jun high C = 23.5
| Jul high C = 25.6
| Aug high C = 25.0
| Sep high C = 20.2
| Oct high C = 14.5
| Nov high C = 8.0
| Dec high C = 4.3
| year high C = 14.8
| Jan mean C = 1.2
| Feb mean C = 1.9
| Mar mean C = 5.9
| Apr mean C = 9.9
| May mean C = 14.0
| Jun mean C = 17.7
| Jul mean C = 19.4
| Aug mean C = 18.8
| Sep mean C = 14.6
| Oct mean C = 10.1
| Nov mean C = 5.0
| Dec mean C = 1.9
| year mean C = 10.0
| Jan low C = −1.5
| Feb low C = −1.7
| Mar low C = 1.2
| Apr low C = 4.3
| May low C = 8.5
| Jun low C = 12.1
| Jul low C = 13.6
| Aug low C = 13.5
| Sep low C = 9.8
| Oct low C = 6.5
| Nov low C = 2.3
| Dec low C = -0.5
| year low C = 5.7
|precipitation colour = green
| Jan precipitation mm = 63
| Feb precipitation mm = 53
| Mar precipitation mm = 61
| Apr precipitation mm = 63
| May precipitation mm = 98
| Jun precipitation mm = 92
| Jul precipitation mm = 98
| Aug precipitation mm = 98
| Sep precipitation mm = 70
| Oct precipitation mm = 72
| Nov precipitation mm = 69
| Dec precipitation mm = 81
| year precipitation mm = 920
| Jan snow cm = 8
| Feb snow cm = 9
| Mar snow cm = 3
| Apr snow cm = 0.
| May snow cm = 0
| Jun snow cm = 0
| Jul snow cm = 0
| Aug snow cm = 0
| Sep snow cm = 0
| Oct snow cm = 0
| Nov snow cm = 2
| Dec snow cm = 10
| year snow cm = 32
|unit precipitation days = 1.0 mm
| Jan precipitation days = 9.6
| Feb precipitation days = 8.6
| Mar precipitation days = 9.5
| Apr precipitation days = 10.2
| May precipitation days = 11.6
| Jun precipitation days = 11.3
| Jul precipitation days = 10.9
| Aug precipitation days = 11.2
| Sep precipitation days = 8.5
| Oct precipitation days = 10.1
| Nov precipitation days = 9.8
| Dec precipitation days = 11.6
| year precipitation days = 122.9
|unit snow days = 1.0 cm
| Jan snow days = 2.8
| Feb snow days = 2.5
| Mar snow days = 1.1
| Apr snow days = 0.1
| May snow days = 0
| Jun snow days = 0
| Jul snow days = 0
| Aug snow days = 0
| Sep snow days = 0
| Oct snow days = 0.1
| Nov snow days = 0.7
| Dec snow days = 2.4
| year snow days = 9.7
|source 1 = MeteoSwiss {{cite web
|url=https://www.meteoswiss.admin.ch/product/output/climate-data/climate-diagrams-normal-values-station-processing/BUS/climsheet_BUS_np9120_e.pdf
|title=Climate normals Buchs / Aarau
|work=Climate diagrams and normals from Swiss measuring stations
|publisher=Federal Office of Meteorology and Climatology (MeteoSwiss)
|accessdate=11 September 2022
|archive-date=7 July 2022
|archive-url=https://web.archive.org/web/20220707103416/https://www.meteoswiss.admin.ch/product/output/climate-data/climate-diagrams-normal-values-station-processing/BUS/climsheet_BUS_np9120_e.pdf
|url-status=dead
}}
|date=16 December 2021
}}
Between approximately {{convert|1050|to|1390|m}}, the climate changes to either a humid continental climate (Dfb under the Köppen system), or a subpolar oceanic climate (Cfc), depending on location. As elevation increases, the winters become colder and the summers become shorter. A mixture of conifer and deciduous trees occupy this montane zone, leading to a change in ecoregion to Alps conifer and mixed forests.
{{Weather box
|location = Scuol (1991–2020), {{convert|1304|m|ft}}, {{coord|46.79|N|10.28|E|region:CH_type:city}}
|collapsed = yes
|metric first = Yes
|single line = Yes
| Jan high C = 0.0
| Feb high C = 2.9
| Mar high C = 8.7
| Apr high C = 13.0
| May high C = 17.1
| Jun high C = 21.1
| Jul high C = 23.1
| Aug high C = 22.6
| Sep high C = 18.1
| Oct high C = 13.2
| Nov high C = 5.8
| Dec high C = 0.3
| year high C = 12.2
| Jan mean C = −4.3
| Feb mean C = −2.7
| Mar mean C = 1.8
| Apr mean C = 6.0
| May mean C = 10.3
| Jun mean C = 13.8
| Jul mean C = 15.5
| Aug mean C = 15.0
| Sep mean C = 11.0
| Oct mean C = 6.5
| Nov mean C = 0.9
| Dec mean C = −3.3
| year mean C = 5.9
| Jan low C = −8.0
| Feb low C = −7.3
| Mar low C = −3.5
| Apr low C = 0.1
| May low C = 4.3
| Jun low C = 7.6
| Jul low C = 9.3
| Aug low C = 9.3
| Sep low C = 5.6
| Oct low C = 1.8
| Nov low C = −2.8
| Dec low C = −6.7
| year low C = 0.8
|precipitation colour = green
| Jan precipitation mm = 38
| Feb precipitation mm = 27
| Mar precipitation mm = 34
| Apr precipitation mm = 35
| May precipitation mm = 53
| Jun precipitation mm = 80
| Jul precipitation mm = 88
| Aug precipitation mm = 109
| Sep precipitation mm = 65
| Oct precipitation mm = 69
| Nov precipitation mm = 63
| Dec precipitation mm = 47
| year precipitation mm = 708
| Jan snow cm = 51
| Feb snow cm = 39
| Mar snow cm = 20
| Apr snow cm = 7
| May snow cm = 1
| Jun snow cm = 0
| Jul snow cm = 0
| Aug snow cm = 0
| Sep snow cm = 0
| Oct snow cm = 6
| Nov snow cm = 24
| Dec snow cm = 49
| year snow cm = 197
|unit precipitation days = 1.0 mm
| Jan precipitation days = 5.9
| Feb precipitation days = 4.9
| Mar precipitation days = 5.2
| Apr precipitation days = 6.0
| May precipitation days = 9.1
| Jun precipitation days = 10.6
| Jul precipitation days = 11.0
| Aug precipitation days = 11.8
| Sep precipitation days = 8.0
| Oct precipitation days = 8.0
| Nov precipitation days = 7.2
| Dec precipitation days = 6.8
| year precipitation days = 94.5
|unit snow days = 1.0 cm
| Jan snow days = 7.8
| Feb snow days = 6.3
| Mar snow days = 4.0
| Apr snow days = 1.8
| May snow days = 0.2
| Jun snow days = 0
| Jul snow days = 0
| Aug snow days = 0
| Sep snow days = 0
| Oct snow days = 0.6
| Nov snow days = 4.3
| Dec snow days = 7.4
| year snow days = 32.4
|source 1 = MeteoSwiss {{cite web
|url = https://www.meteoswiss.admin.ch/product/output/climate-data/climate-diagrams-normal-values-station-processing/SCU/climsheet_SCU_np9120_e.pdf
|title = Climate normals Scoul
|work = Climate diagrams and normals from Swiss measuring stations
|publisher = Federal Office of Meteorology and Climatology (MeteoSwiss)
|access-date = 11 September 2022
|archive-date = 15 January 2022
|archive-url = https://web.archive.org/web/20220115043244/https://www.meteoswiss.admin.ch/product/output/climate-data/climate-diagrams-normal-values-station-processing/SCU/climsheet_SCU_np9120_e.pdf
|url-status = dead
}} The weather station elevation is 1303 meters above sea level.
|date=16 December 2021
}}
Between approximately {{convert|1390|to|1880|m}}, the climate becomes subarctic (Dfc under the Köppen system), with even shorter summers. The shorter growing season shifts the forest to be purely coniferous.
{{Weather box
|location = Samedan (1991–2020), {{convert|1709|m|ft}}, {{coord|46.53|N|9.88|E|region:CH_type:city}}
|collapsed = yes
|metric first = Yes
|single line = Yes
| Jan high C = −1.3
| Feb high C = 0.5
| Mar high C = 4.0
| Apr high C = 7.9
| May high C = 12.9
| Jun high C = 17.0
| Jul high C = 19.3
| Aug high C = 18.8
| Sep high C = 14.6
| Oct high C = 10.5
| Nov high C = 4.1
| Dec high C = −0.7
| year high C = 9.0
| Jan mean C = −8.4
| Feb mean C = −7.1
| Mar mean C = −2.4
| Apr mean C = 1.9
| May mean C = 6.7
| Jun mean C = 10.5
| Jul mean C = 12.3
| Aug mean C = 11.8
| Sep mean C = 7.9
| Oct mean C = 3.6
| Nov mean C = −2.1
| Dec mean C = −7.0
| year mean C = 2.3
| Jan low C = −15.8
| Feb low C = −15.6
| Mar low C = −9.6
| Apr low C = −4.3
| May low C = 0.1
| Jun low C = 3.2
| Jul low C = 4.7
| Aug low C = 4.7
| Sep low C = 1.3
| Oct low C = −2.6
| Nov low C = −7.8
| Dec low C = −13.4
| year low C = −4.6
|precipitation colour = green
| Jan precipitation mm = 29
| Feb precipitation mm = 19
| Mar precipitation mm = 24
| Apr precipitation mm = 37
| May precipitation mm = 67
| Jun precipitation mm = 91
| Jul precipitation mm = 87
| Aug precipitation mm = 100
| Sep precipitation mm = 73
| Oct precipitation mm = 77
| Nov precipitation mm = 70
| Dec precipitation mm = 37
| year precipitation mm = 710
| Jan snow cm = 51
| Feb snow cm = 42
| Mar snow cm = 30
| Apr snow cm = 21
| May snow cm = 4
| Jun snow cm = 0
| Jul snow cm = 0
| Aug snow cm = 0
| Sep snow cm = 2
| Oct snow cm = 12
| Nov snow cm = 40
| Dec snow cm = 52
| year snow cm = 254
|unit precipitation days = 1.0 mm
| Jan precipitation days = 5.2
| Feb precipitation days = 4.2
| Mar precipitation days = 4.3
| Apr precipitation days = 6.0
| May precipitation days = 9.2
| Jun precipitation days = 11.0
| Jul precipitation days = 10.6
| Aug precipitation days = 11.0
| Sep precipitation days = 8.0
| Oct precipitation days = 8.1
| Nov precipitation days = 7.9
| Dec precipitation days = 6.1
| year precipitation days = 91.6
| unit snow days = 1.0 cm
| Jan snow days = 8.8
| Feb snow days = 8.0
| Mar snow days = 6.9
| Apr snow days = 5.1
| May snow days = 1.1
| Jun snow days = 0.2
| Jul snow days = 0.1
| Aug snow days = 0.0
| Sep snow days = 0.5
| Oct snow days = 2.6
| Nov snow days = 6.7
| Dec snow days = 9.5
| year snow days = 49.5
|source 1 = MeteoSwiss {{cite web
|url = https://www.meteoswiss.admin.ch/product/output/climate-data/climate-diagrams-normal-values-station-processing/SAM/climsheet_SAM_np9120_e.pdf
|title = Climate normals Samedan
|work = Climate diagrams and normals from Swiss measuring stations
|publisher = Federal Office of Meteorology and Climatology (MeteoSwiss)
|access-date = 11 September 2022
|archive-date = 14 January 2022
|archive-url = https://web.archive.org/web/20220114041926/https://www.meteoswiss.admin.ch/product/output/climate-data/climate-diagrams-normal-values-station-processing/SAM/climsheet_SAM_np9120_e.pdf
|url-status = dead
}} The weather station elevation is 1708 meters above sea level.
|date=16 December 2021
}}
At about {{convert|1880|m|ft}}, the climate becomes too cold to support trees, and is classified as an alpine climate (ET under the Köppen system). The summers become cool and only grasses and low plants are adapted to grow. This alpine climate extends to approximately {{convert|3250|m|ft}}.
{{Weather box
|location = Weissfluhjoch (1991–2020), {{convert|2690|m|ft}}, {{Coord|46.833|N|9.806|E|region:CH-GR_type:mountain|name=Weissfluhjoch}}
|collapsed=yes
|metric first = Yes
|single line = Yes
| Jan high C = −5.3
| Feb high C = −5.9
| Mar high C = −4.1
| Apr high C = −1.5
| May high C = 2.7
| Jun high C = 7.3
| Jul high C = 10.2
| Aug high C = 10.6
| Sep high C = 6.5
| Oct high C = 3.4
| Nov high C = −1.7
| Dec high C = −4.3
| year high C = 1.5
| Jan mean C = −7.8
| Feb mean C = −8.5
| Mar mean C = −6.6
| Apr mean C = −4.0
| May mean C = 0.1
| Jun mean C = 3.9
| Jul mean C = 6.2
| Aug mean C = 6.6
| Sep mean C = 3.0
| Oct mean C = 0.3
| Nov mean C = −4.2
| Dec mean C = −6.9
| year mean C = −1.5
| Jan low C = −10.4
| Feb low C = −11.2
| Mar low C = −9.3
| Apr low C = −6.5
| May low C = −2.3
| Jun low C = 1.3
| Jul low C = 3.2
| Aug low C = 3.7
| Sep low C = 0.5
| Oct low C = −2.2
| Nov low C = −6.7
| Dec low C = −9.6
| year low C = −4.1
|precipitation colour = green
| Jan precipitation mm = 108
| Feb precipitation mm = 80
| Mar precipitation mm = 96
| Apr precipitation mm = 79
| May precipitation mm = 116
| Jun precipitation mm = 166
| Jul precipitation mm = 181
| Aug precipitation mm = 198
| Sep precipitation mm = 123
| Oct precipitation mm = 97
| Nov precipitation mm = 92
| Dec precipitation mm = 103
| year precipitation mm = 1439
| Jan snow cm = 131
| Feb snow cm = 117
| Mar snow cm = 123
| Apr snow cm = 91
| May snow cm = 63
| Jun snow cm = 36
| Jul snow cm = 14
| Aug snow cm = 12
| Sep snow cm = 35
| Oct snow cm = 63
| Nov snow cm = 118
| Dec snow cm = 136
| year snow cm = 939
|unit precipitation days = 1.0 mm
| Jan precipitation days = 10.5
| Feb precipitation days = 9.6
| Mar precipitation days = 12.0
| Apr precipitation days = 11.6
| May precipitation days = 14.2
| Jun precipitation days = 15.4
| Jul precipitation days = 15.2
| Aug precipitation days = 15.0
| Sep precipitation days = 12.1
| Oct precipitation days = 10.0
| Nov precipitation days = 10.9
| Dec precipitation days = 11.0
| year precipitation days = 147.5
|unit snow days = 1.0 cm
| Jan snow days = 12.9
| Feb snow days = 11.8
| Mar snow days = 14.3
| Apr snow days = 12.7
| May snow days = 10.
| Jun snow days = 5.5
| Jul snow days = 2.5
| Aug snow days = 2.0
| Sep snow days = 5.8
| Oct snow days = 8.1
| Nov snow days = 12.9
| Dec snow days = 14.3
| year snow days = 113.-0
|source 1 = MeteoSwiss {{cite web
| url = https://www.meteoswiss.admin.ch/product/output/climate-data/climate-diagrams-normal-values-station-processing/WFJ/climsheet_WFJ_np9120_e.pdf
| title = Climate normals Weissfluhjoch
| work = Climate diagrams and normals from Swiss measuring stations
| publisher = Federal Office of Meteorology and Climatology (MeteoSwiss)
| accessdate = 11 September 2022
| archive-date = 29 January 2022
| archive-url = https://web.archive.org/web/20220129221807/https://www.meteoswiss.admin.ch/product/output/climate-data/climate-diagrams-normal-values-station-processing/WFJ/climsheet_WFJ_np9120_e.pdf
| url-status = dead
}} The weather station elevation is 2690 meters above sea level.
|date=16 December 2021
}}
Above approximately {{convert|3250|m|ft}}, the climate transitions to an ice cap climate, where the mean temperature from 1976-2000 was always below {{convert|0|C|F}}. At these altitudes, no plants can grow and the ground is either rock or ice. At 3571m and from 1991 through 2020, Jungfraujoch had an ET climate, with an August mean temperature of {{convert|0.6|C|F|0}}. Glaciers, such as the Aletsch Glacier, still surround Jungfrau, but are starting to melt due to climate change.{{cite journal|
last1=Jouvet|first1=G|last2=Huss|first2=M|title=Future retreat of Great Aletsch Glacier|journal=Journal of Glaciology|year=2019|volume=65|issue=253|pages=869–872|doi=10.1017/jog.2019.52|hdl=20.500.11850/370494|hdl-access=free}}
{{Weather box
|location = Jungfraujoch, elevation: {{convert|3571|m|ft|0|abbr=on}}, 1991–2020 normals, extremes 1973–present, {{Coord|46.548|N|7.987|E|region:CH-GR_type:mountain|name=Jungfraujoch}}
|collapsed = yes
|metric first = Yes
|single line = Yes
|Jan record high C = 4.2
|Feb record high C = 2.9
|Mar record high C = 8.2
|Apr record high C = 4.9
|May record high C = 10.0
|Jun record high C = 13.1
|Jul record high C = 14.3
|Aug record high C = 12.8
|Sep record high C = 11.6
|Oct record high C = 10.0
|Nov record high C = 4.5
|Dec record high C = 7.1
|Jan high C = -9.5
|Feb high C = -10.2
|Mar high C = -8.6
|Apr high C = -6.3
|May high C = -2.1
|Jun high C = 1.7
|Jul high C = 3.4
|Aug high C = 3.5
|Sep high C = 0.5
|Oct high C = -2.2
|Nov high C = -6.5
|Dec high C = -8.7
|year high C = -3.8
|Jan mean C = -12.5
|Feb mean C = -13.3
|Mar mean C = -11.6
|Apr mean C = -9.4
|May mean C = -5.2
|Jun mean C = -1.5
|Jul mean C = 0.4
|Aug mean C = 0.6
|Sep mean C = -2.4
|Oct mean C = -4.9
|Nov mean C = -9.2
|Dec mean C = -11.7
|year mean C = -6.7
|Jan low C = -15.5
|Feb low C = -16.3
|Mar low C = -14.4
|Apr low C = -12.0
|May low C = -7.8
|Jun low C = -4.0
|Jul low C = -2.1
|Aug low C = -1.7
|Sep low C = -4.7
|Oct low C = -7.4
|Nov low C = -11.8
|Dec low C = -14.5
|year low C = -9.4
|Jan record low C = -34.2
|Feb record low C = -35.4
|Mar record low C = -28.9
|Apr record low C = -25.2
|May record low C = -22.0
|Jun record low C = -16.4
|Jul record low C = -14.0
|Aug record low C = -13.0
|Sep record low C = -16.0
|Oct record low C = -21.7
|Nov record low C = -30.0
|Dec record low C = -30.7
|Jan humidity = 63
|Feb humidity = 65
|Mar humidity = 67
|Apr humidity = 72
|May humidity = 78
|Jun humidity = 77
|Jul humidity = 76
|Aug humidity = 74
|Sep humidity = 71
|Oct humidity = 66
|Nov humidity = 68
|Dec humidity = 65
|year humidity = 70
|Jan sun = 117
|Feb sun = 122
|Mar sun = 161
|Apr sun = 160
|May sun = 152
|Jun sun = 170
|Jul sun = 181
|Aug sun = 183
|Sep sun = 175
|Oct sun = 145
|Nov sun = 106
|Dec sun = 101
|year sun = 1773
|Jan percentsun = 49
|Feb percentsun = 51
|Mar percentsun = 48
|Apr percentsun = 44
|May percentsun = 37
|Jun percentsun = 40
|Jul percentsun = 43
|Aug percentsun = 48
|Sep percentsun = 50
|Oct percentsun = 53
|Nov percentsun = 44
|Dec percentsun = 45
|year percentsun = 45
|source 1 = MeteoSwiss{{cite web
| url = https://www.meteoswiss.admin.ch/product/output/climate-data/climate-diagrams-normal-values-station-processing/JUN/climsheet_JUN_np9120_e.pdf
| title = Climate Normals Jungfraujoch (Reference period 1991−2020)
| publisher = Swiss Federal Office of Meteorology and Climatology, MeteoSwiss
| archive-date = 28 January 2022
| archive-url = https://web.archive.org/web/20220128001744/https://www.meteoswiss.admin.ch/product/output/climate-data/climate-diagrams-normal-values-station-processing/JUN/climsheet_JUN_np9120_e.pdf
| url-status = dead
| access-date = 27 January 2022}}
|source 2 = Infoclimat.fr (extremes){{Cite web|url=https://www.infoclimat.fr/climatologie/normales-records/1981-2010/jungfraujoch/valeurs/06730.html|title=Normales et records climatologiques 1981-2010 à Jungfraujoch - Infoclimat|website=www.infoclimat.fr|access-date=2019-08-03}}
}}