Edición de «Humidex»

[[Archivo:Humidex plot.svg|miniaturadeimagen|Gráfico de los valores de humidex en función de la temperatura y la humedad relativa]]
El '''humidex''' (abreviatura del '''índice de humedad''') es un número de índice utilizado por los meteorólogos canadienses para describir qué tan caluroso es el clima para la persona promedio, combinando el efecto del calor y la humedad. El término humidex es una innovación canadiense acuñada en 1965.<ref>{{Cita web|url=https://ec.gc.ca/meteo-weather/default.asp?lang=En&n=6C5D4990-1|título=Spring and Summer Hazards|fechaacceso=22 de septiembre de 2016|autor=|nombre=|fecha=|sitioweb=Environment and Climate Changes|editorial=Government of Canada}}</ref> El humidex es una [[Magnitud adimensional|cantidad adimensional]] basada en el [[punto de rocío]].

'''''Gama de humidex: Escala de confort:'''''<ref name="SMC">{{Cita web|url=http://ec.gc.ca/meteo-weather/default.asp?lang=En&n=6C5D4990-1#humidex|título=Humidex|fechaacceso=20 de junio de 2016|autor=Meteorological Service of Canada|sitioweb=Spring and Summer Weather Hazards|editorial=Environment Canada}}</ref><ref>{{Cita web|url=https://www.thestar.com/news/starweather/2015/08/7-things-you-probably-didn-t-know-about-the-humidex.html|título=7 things you probably didn't know about the Humidex|fechaacceso=23 de septiembre de 2016|autor=Hong|nombre=Jackie|sitioweb=TheStar.com|editorial=The Star}}</ref>

* 20 a 29: poco o nada de incomodidad
* 30 a 39: algunas molestias
* 40 a 45: Gran incomodidad; evitar el esfuerzo
* Por encima de 45: Peligroso; golpe de calor bastante posible

== Historia ==
La fórmula actual para determinar el humidex fue desarrollada por J. M. Masterton y F. A. Richardson del Servicio de Ambiente Atmosférico de Canadá en 1979. Humidex difiere del índice de calor utilizado en los Estados Unidos en que se deriva del punto de rocío en lugar de la [[humedad relativa]].

Durante mucho tiempo, el récord de humidex en Canadá fue establecido por Windsor, Ontario, que llegó a 52.1 el 20 de junio de 1953, según informó ''Environment Canada''.<ref>{{Cita web|url=https://canada.ca/en/environment-climate-change/services/seasonal-weather-hazards/spring-summer.html#heat_and_humidity|título=Spring and Summer Weather Hazards: Heat and Humidity|fechaacceso=5 de julio de 2018|editorial=Environment and Climate Change Canada|urlarchivo=https://web.archive.org/web/20180714221713/https://www.canada.ca/en/environment-climate-change/services/seasonal-weather-hazards/spring-summer.html#heat_and_humidity|fechaarchivo=14 de julio de 2018}}</ref>

Este valor fue superado el 25 de julio de 2007 cuando Carman, Manitoba, llegó a 53.<ref>{{Cita web |url=http://www.cbc.ca/canada/manitoba/story/2007/07/26/storm-sewage.html |título=Cbc.ca |fechaacceso=31 de diciembre de 2018 |urlarchivo=https://web.archive.org/web/20090116104229/http://www.cbc.ca/canada/manitoba/story/2007/07/26/storm-sewage.html |fechaarchivo=16 de enero de 2009 }}</ref><ref>{{Cita web|url=https://ec.gc.ca/meteo-weather/default.asp?lang=En&n=5EBCEA59-1|título=Canada's Top Ten Weather Stories for 2007|fechaacceso=15 de enero de 2017|editorial=Environment and Climate Change Canada}}</ref>

== La fórmula de cálculo de humidex ==
Cuando la [[temperatura]] es de 30&nbsp;°C (86&nbsp;°F) y el punto de rocío es de 15&nbsp;°C (59&nbsp;°F), el humidex es 34. Si la temperatura sigue siendo de 30&nbsp;°C y el punto de rocío aumenta a 25&nbsp;°C (77&nbsp;°F), el humidex se eleva a 42. El humidex es más alto que el índice de calor de EE. UU. A la misma temperatura y humedad relativa.

La fórmula de humidex es la siguiente:<ref>{{Cita web|url=http://climate.weatheroffice.gc.ca/prods_servs/normals_documentation_e.html|título=Calculation of the 1981 to 2010 Climate Normals for Canada|fechaacceso=4 de octubre de 2014|editorial=|urlarchivo=https://web.archive.org/web/20130627223738/http://climate.weatheroffice.gc.ca/prods_servs/normals_documentation_e.html|fechaarchivo=27 de junio de 2013}}</ref>

: <math>H = T_\text{air} + 0.5555 \left[6.11 e^{5417.7530 \left(\frac{1}{273.16} - \frac{1}{273.15+T_\text{dew}}\right)} - 10\right]</math>

donde

* ''H''  Humidex
* ''T''<sub>air</sub> temperatura del aire en °C
* ''T''<sub>dew</sub> es el punto de rocío en °C

5417.7530 es una constante redondeada basada en el peso molecular del agua, el [[calor latente]] de evaporación y la [[Constante de los gases ideales|constante universal de los gases]]. El ajuste de la humedad equivale aproximadamente a un grado de Fahrenheit por cada milibar por el cual la [[presión parcial]] del agua en la atmósfera supera los 10 milibares (10 hPa).

=== Tabla ===
{| class="wikitable" style="text-align: center; height: 200px; border: none; background: none; margin-left: auto; margin-right: auto; font-size: 90%"
|+Humidex
! colspan="2" rowspan="2" style="border: none; background: none;" | 
! colspan="29" |Temperatura (°C, para un rango de 15 - 43&nbsp;°C)
|-
! scope="col" |15
! scope="col" |16
! scope="col" |17
! scope="col" |18
! scope="col" |19
! scope="col" |20
! scope="col" |21
! scope="col" |22
! scope="col" |23
! scope="col" |24
! scope="col" |25
! scope="col" |26
! scope="col" |27
! scope="col" |28
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! scope="col" |30
! scope="col" |31
! scope="col" |32
! scope="col" |33
! scope="col" |34
! scope="col" |35
! scope="col" |36
! scope="col" |37
! scope="col" |38
! scope="col" |39
! scope="col" |40
! scope="col" |41
! scope="col" |42
! scope="col" |43
|-
! rowspan="20" |Punto de rocío<br /><br />(°C)
|-
! scope="row" |10
| style="background: limegreen" |16
| style="background: limegreen" |17
| style="background: limegreen" |18
| style="background: limegreen" |19
| style="background: limegreen" |20
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| style="background: limegreen" |22
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| style="background: limegreen" |29
| style="background: yellow" |30
| style="background: yellow" |31
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| style="background: yellow" |33
| style="background: yellow" |34
| style="background: yellow" |35
| style="background: yellow" |36
| style="background: yellow" |37
| style="background: yellow" |38
| style="background: yellow" |39
| style="background: darkorange" |40
| style="background: darkorange" |41
| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
|-
! scope="row" |11
| style="background: limegreen" |17
| style="background: limegreen" |18
| style="background: limegreen" |19
| style="background: limegreen" |20
| style="background: limegreen" |21
| style="background: limegreen" |22
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| style="background: limegreen" |25
| style="background: limegreen" |26
| style="background: limegreen" |27
| style="background: limegreen" |28
| style="background: limegreen" |29
| style="background: yellow" |30
| style="background: yellow" |31
| style="background: yellow" |32
| style="background: yellow" |33
| style="background: yellow" |34
| style="background: yellow" |35
| style="background: yellow" |36
| style="background: yellow" |37
| style="background: yellow" |38
| style="background: yellow" |39
| style="background: darkorange" |40
| style="background: darkorange" |41
| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
|-
! scope="row" |12
| style="background: limegreen" |17
| style="background: limegreen" |18
| style="background: limegreen" |19
| style="background: limegreen" |20
| style="background: limegreen" |21
| style="background: limegreen" |22
| style="background: limegreen" |23
| style="background: limegreen" |24
| style="background: limegreen" |25
| style="background: limegreen" |26
| style="background: limegreen" |27
| style="background: limegreen" |28
| style="background: limegreen" |29
| style="background: yellow" |30
| style="background: yellow" |31
| style="background: yellow" |32
| style="background: yellow" |33
| style="background: yellow" |34
| style="background: yellow" |35
| style="background: yellow" |36
| style="background: yellow" |37
| style="background: yellow" |38
| style="background: yellow" |39
| style="background: darkorange" |40
| style="background: darkorange" |41
| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
|-
! scope="row" |13
| style="background: limegreen" |18
| style="background: limegreen" |19
| style="background: limegreen" |20
| style="background: limegreen" |21
| style="background: limegreen" |22
| style="background: limegreen" |23
| style="background: limegreen" |24
| style="background: limegreen" |25
| style="background: limegreen" |26
| style="background: limegreen" |27
| style="background: limegreen" |28
| style="background: limegreen" |29
| style="background: yellow" |30
| style="background: yellow" |31
| style="background: yellow" |32
| style="background: yellow" |33
| style="background: yellow" |34
| style="background: yellow" |35
| style="background: yellow" |36
| style="background: yellow" |37
| style="background: yellow" |38
| style="background: yellow" |39
| style="background: darkorange" |40
| style="background: darkorange" |41
| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
| style="background: red; color: white" |46
|-
! scope="row" |14
| style="background: limegreen" |18
| style="background: limegreen" |19
| style="background: limegreen" |20
| style="background: limegreen" |21
| style="background: limegreen" |22
| style="background: limegreen" |23
| style="background: limegreen" |24
| style="background: limegreen" |25
| style="background: limegreen" |26
| style="background: limegreen" |27
| style="background: limegreen" |28
| style="background: limegreen" |29
| style="background: yellow" |30
| style="background: yellow" |31
| style="background: yellow" |32
| style="background: yellow" |33
| style="background: yellow" |34
| style="background: yellow" |35
| style="background: yellow" |36
| style="background: yellow" |37
| style="background: yellow" |38
| style="background: yellow" |39
| style="background: darkorange" |40
| style="background: darkorange" |41
| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
| style="background: red; color: white" |46
|-
! scope="row" |15
| style="background: limegreen" |19
| style="background: limegreen" |20
| style="background: limegreen" |21
| style="background: limegreen" |22
| style="background: limegreen" |23
| style="background: limegreen" |24
| style="background: limegreen" |25
| style="background: limegreen" |26
| style="background: limegreen" |27
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| style="background: limegreen" |29
| style="background: yellow" |30
| style="background: yellow" |31
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| style="background: yellow" |33
| style="background: yellow" |34
| style="background: yellow" |35
| style="background: yellow" |36
| style="background: yellow" |37
| style="background: yellow" |38
| style="background: yellow" |39
| style="background: darkorange" |40
| style="background: darkorange" |41
| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
| style="background: red; color: white" |46
| style="background: red; color: white" |47
|-
! scope="row" |16
|–
| style="background: limegreen" |21
| style="background: limegreen" |22
| style="background: limegreen" |23
| style="background: limegreen" |24
| style="background: limegreen" |25
| style="background: limegreen" |26
| style="background: limegreen" |27
| style="background: limegreen" |28
| style="background: limegreen" |29
| style="background: yellow" |30
| style="background: yellow" |31
| style="background: yellow" |32
| style="background: yellow" |33
| style="background: yellow" |34
| style="background: yellow" |35
| style="background: yellow" |36
| style="background: yellow" |37
| style="background: yellow" |38
| style="background: yellow" |39
| style="background: darkorange" |40
| style="background: darkorange" |41
| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
| style="background: red; color: white" |46
| style="background: red; color: white" |47
| style="background: red; color: white" |48
|-
! scope="row" |17
|–
|–
| style="background: limegreen" |22
| style="background: limegreen" |23
| style="background: limegreen" |24
| style="background: limegreen" |25
| style="background: limegreen" |26
| style="background: limegreen" |27
| style="background: limegreen" |28
| style="background: limegreen" |29
| style="background: yellow" |30
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| style="background: yellow" |38
| style="background: yellow" |39
| style="background: darkorange" |40
| style="background: darkorange" |41
| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
| style="background: red; color: white" |46
| style="background: red; color: white" |47
| style="background: red; color: white" |48
|-
! scope="row" |18
|–
|–
|–
| style="background: limegreen" |24
| style="background: limegreen" |25
| style="background: limegreen" |26
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| style="background: yellow" |30
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| style="background: darkorange" |40
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| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
| style="background: red; color: white" |46
| style="background: red; color: white" |47
| style="background: red; color: white" |48
| style="background: red; color: white" |49
|-
! scope="row" |19
|–
|–
|–
|–
| style="background: limegreen" |26
| style="background: limegreen" |27
| style="background: limegreen" |28
| style="background: limegreen" |29
| style="background: yellow" |30
| style="background: yellow" |31
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| style="background: yellow" |34
| style="background: yellow" |35
| style="background: yellow" |36
| style="background: yellow" |37
| style="background: yellow" |38
| style="background: yellow" |39
| style="background: darkorange" |40
| style="background: darkorange" |41
| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
| style="background: red; color: white" |46
| style="background: red; color: white" |47
| style="background: red; color: white" |48
| style="background: red; color: white" |49
| style="background: red; color: white" |50
|-
! scope="row" |20
|–
|–
|–
|–
|–
| style="background: limegreen" |28
| style="background: limegreen" |29
| style="background: yellow" |30
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| style="background: darkorange" |40
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| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
| style="background: red; color: white" |46
| style="background: red; color: white" |47
| style="background: red; color: white" |48
| style="background: red; color: white" |49
| style="background: red; color: white" |50
| style="background: red; color: white" |51
|-
! scope="row" |21
|–
|–
|–
|–
|–
|–
| style="background: limegreen" |29
| style="background: yellow" |30
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| style="background: yellow" |39
| style="background: darkorange" |40
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| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
| style="background: red; color: white" |46
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| style="background: red; color: white" |48
| style="background: red; color: white" |49
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|-
! scope="row" |22
|–
|–
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|–
| style="background: yellow" |31
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| style="background: darkorange" |40
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| style="background: red; color: white" |46
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|-
! scope="row" |23
|–
|–
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| style="background: yellow" |33
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| style="background: yellow" |39
| style="background: darkorange" |40
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| style="background: red; color: white" |46
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| style="background: red; color: white" |52
| style="background: red; color: white" |53
|-
! scope="row" |24
|–
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|–
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| style="background: yellow" |35
| style="background: yellow" |36
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| style="background: yellow" |39
| style="background: darkorange" |40
| style="background: darkorange" |41
| style="background: darkorange" |42
| style="background: darkorange" |43
| style="background: darkorange" |44
| style="background: darkorange" |45
| style="background: red; color: white" |46
| style="background: red; color: white" |47
| style="background: red; color: white" |48
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| style="background: red; color: white" |51
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| style="background: red; color: white" |54
|-
! scope="row" |25
|–
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| style="background: yellow" |37
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| style="background: darkorange" |40
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| style="background: darkorange" |43
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| style="background: red; color: white" |46
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| style="background: red; color: white" |55
|-
! scope="row" |26
|–
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| style="background: yellow" |39
| style="background: darkorange" |40
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| style="background: darkorange" |45
| style="background: red; color: white" |46
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|-
! scope="row" |27
|–
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| style="background: darkorange" |42
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| style="background: red; color: white" |46
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|-
! scope="row" |28
|–
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| style="background: darkorange" |44
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== Véase también ==

* [[Temperatura de bochorno|Índice de calor]] 
* [[Confort higrotérmico]]
* [[Temperatura de sensación|Sensación térmica]]

== Referencias ==
<references group="" responsive=""></references>

{{Control de autoridades}}
[[Categoría:Clima de Canadá]]
[[Categoría:Introducciones de 1979]]