Humid subtropical climate
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226125003
2008-07-16T22:43:30Z
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/* Characteristics and variants */
[[Image:Subtropworldmap.PNG|thumb|right|350px|''Humid subtropical climate'' zones of the world]] '''Humid subtropical climate''' ([[Köppen climate classification|Köppen]] ''Cfa'' or ''Cwa'') is a climate zone characterized by hot, humid summers and chilly to mild winters. This climate type covers a broad category of climates, and the term "subtropical" may be a misnomer for the winter climate in the cooler areas within this category; in fact [[Wladimir Köppen]] never talked about a humid subtropical climate, but rather about a '''sinic climate''' (''sinisches Klima''), for his subclass ''Cw'' of temperate climates. Significant amounts of precipitation occur in all seasons in most areas. Winter rainfall (and sometimes [[snowfall]]) is associated with large [[storm]]s that the [[westerlies]] steer from west to east. Most summer rainfall occurs during [[thunderstorm]]s and an occasional [[tropical storm]], [[Tropical cyclone|hurricane]] or cyclone.
Humid subtropical climates lie on the southeast side of all [[continent]]s except [[Antarctica]], roughly between [[latitude]]s 25° and 40° north and south. One of the only exceptions where this climate zone reaches up to latitude 46° North, are the [[Po Valley]] and the [[Toulouse]] regions in Europe.
The definition of this climate is for the coldest month mean temperature to be between -3°C and 18°C, and the warmest month to be above 22°C.; and either a dry winter with less than one tenth of the precipitation of the wettest summer month (Köppen: w) or without dry season (Köppen: f, winter months get more than one tenth of the precipitation of the wettest summer month and summer months get at least 40mm per month or more than one third as much the wettest winter month).<ref>''The Times Atlas of the World'' (1993). Times Books ISBN 0-7230-0492-7.</ref>
==Africa==
In Africa this climate is only found in a relatively small area on the South East coast of the continent. Here it is confined to a coastal strip of [[South Africa]] from around the [[Mzimvubu River]] in the [[Eastern Cape]] northeast through [[KwaZulu Natal]] to around the border with [[Mozambique]]. To the southwest temperatures in summer are not high enough to qualify as subtropical and the climate shades into [[oceanic climate|oceanic]] ('''Cfb'''); to the northeast this climate transitions into a tropical [[savanna]] climate ('''Aw''') in Mozambique. The humid subtropical climate is confined to a narrow coastal zone by the [[Drakensberg]] mountains.
The climate of this region is characterised by oceanic influences that give mild temperatures especially in winter when temperatures do not drop as low as in many other regions within the humid subtropical category. For example [[Richards Bay]] experiences a daily average minumum of 12 °C and a daily average maximum of 23 °C in the coldest month and did not drop below 4 °C in the 30 years of records from 1961. Rainfall is distributed throughout the year but is heavier in summer with a high of 172 mm for January and a low of 57 mm for June at Richards Bay.
==Asia==
Humid subtropical climates in Asia differ from those in other continents in generally having a very pronounced dry winter even on the poleward boundary of this region. They occupy extensive arcs of relatively low land from northern [[Pakistan]] circling the [[Himalayas]] to [[China]], Southern Coast of [[South Korea]] and [[Japan]] (most part of [[Honshu]], [[Kyūshū]] and [[Shikoku]]). Some major Asian cities in this climate zone include [[Kathmandu]], [[Chongqing]], [[Chengdu]], [[Shanghai]], [[Nanjing]], [[Busan]], [[Kyoto]] and [[Tokyo]]. [[Hong Kong]] and [[Taipei]] are on the equatorward boundary of this zone.
In most of this region, there is very little precipiation during the winter owing to the powerful anticyclonic winds from Siberia. Only in those parts of coast eastern China between about the [[Huang He|Yellow River]] and the [[Pearl River (China)|Pearl River]] is there sufficient winter rainfall to produce a '''Cfa''' climate and even in these areas rainfall and [[runoff (water)|streamflow]] show a very pronounced summer peak quite unlike other regions of this climate type. The ''only'' area where the winter rainfall equals the summer rain is on the "San-in" ([[Sea of Japan]]) coast of Japan, which during winter is effectively on the windward side of the westerlies. The winter rainfall in these regions is usually produced by low pressure systems off the east coast that develop in the onshore flow from the Siberian High. Summer rainfall comes from the East Asian Monsoon and from frequent [[typhoon]]s.
Annual rainfall is generally over 1,000 mm (40 inches), and in areas below the Himalayas can be much higher still. In the west humid subtropical climate border on continental climates as [[altitude]] increases, or on winter-rainfall climates in Pakistan.
===Isolated humid zones in western Asia===
Although humid climates in Asia are mostly confined to the southeastern quarter of the continent, there are some isolated areas on the [[Black Sea|Black]] and Caspian Seas than possess humid climates that are unusually warm for their high latitudes.
In the narrow [[Caspian Sea|Caspian]] coastal strip of [[Iran]] ([[Gilan Province|Gilan]] and [[Māzandarān Province|Mazandaran]]) a humid subtropical climate prevails at an unusually high latitude. Annual rainfall ranges from around 740 mm (29 inches) at [[Sari, Iran|Sari]] to over 2,000 mm (78 inches) at [[Bandar-e Anzali]], and is heavy throughout the year, with a maximum in October or November when [[Bandar-e Anzali]] can average 400 millimetres (16 inches). Tempteratures are generally moderate in comparison with other parts of western Asia. In [[Rasht]], the average maximum in July is around 28 °C (82 °F) but with near-saturation [[humidity]], whilst in January it is around 9 °C (48 °F).
In [[Georgia (country)|Georgia]] and the adjacent region of [[Turkey]], the [[Colchis|Kolkheti Lowland]] has a climate similar to that of Gilan in Iran. Temperatures range from 22 °C in summer to 5 °C in winter and rainfall is even heavier than in Caspian Iran, up to 2,300 millimetres per year in [[Hopa]], and it falls throughout the year. This climate is almost a '''Cfa'''/'''Cfb''' borderline case, however.
==Australia==
The humid subtropical climate dominates most of eastern Australia south from about [[Bundaberg, Queensland|Bundaberg]], [[Queensland]] down to about [[Bega, New South Wales|Bega]] on the south coast of [[New South Wales]]. It extends from the coast inland to about [[Dubbo, New South Wales|Dubbo]] and the [[Warrumbungle Range|Warrumbungle]] and [[Nandewar Range|Nandewar]] mountain ranges, where it grades into arid climates. In the [[Great Dividing Range]] and to the south of about Bega, this climate type grades into [[oceanic climate|warm temperate climates]] (Köppen '''Cfb''') as at [[Guyra, New South Wales|Guyra]] and [[Katoomba, New South Wales|Katoomba]], in New South Wales.
This zone contains the only regions where [[soil]]s are not acutely deficient in [[phosphorus]], as well as the heaviest rainfall south of the Tropic of Capricorn, making it prime agricultural country, centred on towns such as [[Coffs Harbour, New South Wales|Coffs Harbour]], [[Grafton, New South Wales|Grafton]], [[Kempsey, New South Wales|Kempsey]], [[Port Macquarie, New South Wales|Port Macquarie]], [[Tamworth, New South Wales|Tamworth]], and [[Moree, New South Wales|Moree]].
Many of Australia's major cities are also in this climate zone, including [[Sydney, New South Wales|Sydney]], [[Brisbane, Queensland|Brisbane]], [[Gold Coast, Queensland|Gold Coast]]-[[Tweed Heads, New South Wales|Tweed Heads]], [[Newcastle, New South Wales|Newcastle]] and [[Wollongong, New South Wales|Wollongong]].
===Variations in Australia===
There is considerable variation in climate within this zone. Annual rainfall on the coast can reach as high as 2,000 mm (80 inches) in favourable locations and is generally above 1,000 mm (40 inches). However, because most of the heaviest two- and three-day rainfalls in the world occur in this coastal zone as a result of east coast lows forming to the north of a [[anticyclone|large high pressure system]], there can be great variation in rainfall from year to year. At [[Lismore, New South Wales|Lismore]] in the centre of this zone, the annual rainfall can range from less than 550 mm (22 inches) in 1915 to more than 2,780 mm (110 inches) in 1950. There is usually a distinct summer rainfall maximum that becomes more pronounced moving northwards: in Brisbane the wettest month (February) receives five times the rainfall of the driest (Septet text]]very warm but not excessive: the average maximum in January is usually around 28 °C (82 °F) and in July around 19 °C (66 °F). Frosts are extremely rare except at higher elevations.
In the [[Darling Downs]] and further south, the summer rainfall maximum is less marked and by the time one reaches Dubbo, there are actually on average more rainy days in the winter months. Temperatures here are more extreme, with summers being generally very hot with maxima of around 32 °C (90 °F) and frosts being common during dry winters: at [[Mitchell, Queensland|Mitchell]] the temperature has reached as low as -9.4 °C (15 °F).
North of the '''Cfa''' climate zone there is a zone centred upon [[Rockhampton, Queensland|Rockhampton]] and extending up to the [[Atherton Tableland]] of Köppen '''Cwa''' climate. This has a very pronounced dry winter with often negligible rainfall between June and October, and winter temperatures generally only slightly below 14.4°C, above which one would have a tropical savanna, or '''Aw''', climate.
== Europe ==
Some areas of Europe, such as parts of southern France, northern Italy (Po River Valley), and coastal Croatia have summers too warm (>21°C in the warmest month) to qualify as oceanic, no freezing month, and enough summer precipitation to preclude their classification as [[Mediterranean climate|Mediterranean]]. This is a narrow band of climate that could be classified as humid sub-tropical, which includes some densely-populated territory.
==North America==
In [[North America]], humid subtropical climates are almost exclusively the domain of the [[American South]], the eastern half of [[Texas]] (includes South Texas), [[Louisiana]], most of [[Arkansas]], [[Mississippi]], [[Tennessee]], [[Kentucky]], [[Alabama]], [[North Carolina]], [[South Carolina]], [[Georgia (U.S. state)|Georgia]], most of [[Florida]] and [[Virginia]], excluding upland regions of the Appalachians. It also exists in low lying or urban areas including [[Delaware]], southwestern [[West Virginia]], eastern and southern [[Maryland]], southeastern [[Pennsylvania]], most of [[New Jersey]], and southern [[Missouri]], and extreme southern [[Ohio]]. The most classic example of a humid subtropical climate is the deep south, because the summers are long and almost tropical, and it only reaches freezing a few times in the winter with rare snowfall. Summer conditions in this zone are hot and humid, with daily averages ranging between 25°C (77°F) and 30°C (86°F).
Major cities in this climate zone include [[Houston]], [[San Antonio]], [[Austin, Texas|Austin]], [[Dallas]], [[Atlanta]], [[Memphis, Tennessee|Memphis]], [[Mobile, Alabama|Mobile]], [[New Orleans, Louisiana|New Orleans]], [[Lafayette, Louisiana|Lafayette]] ([[Louisiana|LA]]), [[Birmingham, Alabama|Birmingham]] ([[Alabama|AL]]), [[Louisville, Kentucky|Louisville]], [[Nashville]] ,[[Chattanooga]], [[Greenville, South Carolina|Greenville]] ([[South Carolina|SC]]), [[Charlotte]], [[Raleigh, North Carolina|Raleigh]], [[Jackson, Mississippi|Jackson]] ([[MS]]), [[Jacksonville]], [[Orlando, Florida|Orlando]], [[Tampa]], [[Richmond, Virginia|Richmond]], [[Charleston, West Virginia|Charleston]] ([[West Virginia|WV]]) [http://www.wchstv.com/newsroom/wx/climatesummary.shtml] and [[Little Rock]]. Cities on the northern periphery of this zone include [[Tulsa]], [[St. Louis]], [[Cincinnati]], [[Washington, District of Columbia|Washington]] ([[District of Columbia|DC]]), [[Baltimore]], [[Philadelphia]] (northernmost metropolitan area), [[Wilmington, Delaware|Wilmington]] ([[Delaware|DE]]), and [[Atlantic City]]. [[Dallas]] and [[Oklahoma City]] show marked reduction in rainfall that suggests a shading into steppe climates to be found farther west, as in [[Lubbock, Texas]]. There is some debate over whether [[New York City]] falls under this category as its normal coldest average temperature is -1 degree Celsius which under the Koppen definition would qualify it as subtropical.
===Characteristics and variants===
The southernmost limits of this climate are around [[Miami]] and southern coastal [[Texas]], and areas further south have a true [[tropical climate]] with a very warm weather year round and minimal temperature differences between seasons. By contrast, the northernmost limits of the humid subtropical experience much greater seasonal variation. They draw influence from the Atlantic Ocean and its bays, [[Delaware Bay]] and [[Chesapeake Bay]] including [[Washington, D.C.]]. Further away from the Atlantic, it is found at the edge of the [[Blue Ridge Mountains]] west to [[Louisville, Kentucky]], then roughly along the lower [[Ohio River]] through [[Paducah, Kentucky]] to a line south of [[Springfield, Missouri]], that does not include the city itself. Areas further north than this, inland, or at a higher elevation fall into the [[humid continental climate]] category with harsher winters.
[[Snowfall]] varies greatly in this climate zone. In areas around Florida and the [[Gulf Coast]], snowfall is very rare and it occurs at most a few times per generation. In inland southern cities farther north, such as [[Atlanta]], [[Memphis]], [[Little Rock]], [[Nashville]], [[Dallas]], [[Greenville, SC|Greenville]], [[Charlotte, NC|Charlotte]], [[Raleigh, North Carolina|Raleigh]], and [[Norfolk, Virginia|Norfolk]], snowfall is sporadic, but occasional snow and ice storms are not unusual, however most of the winter temperatures remain above or well above freezing with hardy sub-tropical plant growth. In the northern limits of this climate zone, however, cities such as [[Louisville, KY|Louisville]], [[Cincinnati]] and [[Philadelphia]], experience snow every winter, sometimes accumulating heavily although it melts more quickly than in regions to the north.
Precipitation is plentiful in the humid subtropical climate zone. Although most areas tend to have precipitation spread evenly throughout the year, a somewhat [[monsoon]]-like pattern is seen in parts of the Southeast (in locales such as [[Augusta, Georgia]] and [[Columbia, South Carolina]]), which experience dry winters (by humid subtropical standards) and warm spring, followed immediately by a long, hot, rainy and humid summer. In addition, areas in [[Texas]] that are slightly inland from the [[Gulf of Mexico]], such as [[Austin, Texas|Austin]], generally see a peak of precipitation in the spring, and a deep, drought-like nadir in mid-[[summer]].
== South America ==
[[Image:Climate in Southern Brazil.jpg|thumb|right|Humid subtropical climate in [[Brazil]].]]
In South America, this kind of climate can be found mainly at the southern Atlantic Coast. In Southern [[Brazil]] (south of the highlands of the states of [[Rio de Janeiro]] and [[São Paulo]], where the coastal area is tropical), the South of [[Paraguay]], the North of [[Uruguay]] and the North-East of [[Argentina]] (Eastern [[Chaco]], Mesopotamia and the Northern and Central [[Pampas]]) temperatures are within the range of this climate and there is rainfall year-round. South-east of a line between [[Buenos Aires]] and [[Bahía Blanca]] summer temperatures are too low, and west of a line between Bahía Blanca, [[Rosario]], and the cities on the [[Paraná River]] there is a dry period in winter. The region covers three vegetation zones: the subtropical rain forest in [[Misiones Province]] and parts of Southern Brazil, where rainfall and winter temperatures are high (1500 mm of rainfall or more, and temperatures higher than 16°C in winter) but summer temperatures lie below 26°C; the eastern [[Chaco]] and the swamplands of the Argentine [[Corrientes Province]], with less rainfall (800 to 1500 mm) and higher summer temperatures (above 26°C); and the generally cooler Humid Pampas area with warm summers of 22° to 25°C and cool winters of 8° to 12°C which receive great influence by the Oceanic regions of the Atlantic Coast of the region around [[Mar del Plata]].
Summer temperatures in some valleys of southern Central [[Chile]] (the [[Temuco]]/[[Concepción]] area) are around 22°C, but in the greatest part of this region they are below this mark. Another small area with a similar climate is parts of the northern [[Yungas]] in [[Bolivia]] and [[Peru]].
==Examples==
===Northern hemisphere===
{{climate chart|[[New Orleans|New Orleans, USA]]
|6|17|149
|8|18|139
|12|22|133
|14|26|128
|19|29|117
|22|32|173
|23|33|157
|23|33|156
|22|31|141
|16|27|77
|11|22|129
|8|18|129
|float=left
|source=[http://www.weather.com/outlook/travel/businesstraveler/wxclimatology/monthly/graph/USLA0338]
}}
{{climate chart|[[Rize|Rize, Turkey]]
|3|10|217
|4|11|173
|5|12|147
|8|15|101
|12|19|102
|16|23|128
|19|25|136
|19|26|183
|16|23|221
|12|20|272
|9|16|250
|5|13|243
|float=left
|clear=none
|source=[http://www.climate-charts.com/Locations/t/TU17040.php]
}}
{{climate chart|[[Shanghai|Shanghai, China]]
|1|8|48
|1|8|58
|4|13|84
|10|19|94
|15|25|94
|19|28|180
|23|32|147
|23|32|142
|19|28|130
|14|23|71
|7|17|51
|2|17|36
|float=left
|clear=none
|source=[http://www.bbc.co.uk/weather/world/city_guides/results.shtml?tt=TT002130]
}}
{{-}}
===Southern hemisphere===
{{climate chart|[[Buenos Aires|Buenos Aires, Argentina]]
|20|30|119
|19|29|118
|17|26|134
|13|23|97
|10|19|74
|8|16|63
|8|15|66
|8|17|70
|10|19|73
|13|22|119
|15|25|109
|18|28|105
|float=left
|clear=none
|source=[http://www.climate-charts.com/Locations/a/AG87585.php]
}}
{{climate chart|[[Richards Bay|Richards Bay, South Africa]]
|21|29|172
|21|29|167
|20|29|107
|18|27|109
|15|25|109
|12|23|57
|12|23|60
|14|24|65
|16|25|77
|17|25|105
|19|27|114
|20|29|86
|float=left
|clear=none
|source=[http://www.weathersa.co.za/Climat/Climstats/RichardsBayStats.jsp]
}}
{{climate chart|[[Brisbane|Brisbane, Australia]]
|21|29|122
|21|29|111
|19|28|81
|16|26|57
|13|24|115
|10|21|67
|9|21|25
|10|22|43
|13|24|34
|16|26|70
|18|27|103
|20|28|125
|float=left
|clear=none
|source=[http://www.bom.gov.au/climate/averages/tables/cw_040842_All.shtml]
}}
{{-}}
==References==
{{reflist}}
{{Koppen}}
[[Category:Climate|Humid subtropical climate]]
[[fr:Climat subtropical humide]]
[[ko:온대 습윤 기후]]
[[he:אקלים סובטרופי גשום]]
[[ja:温暖湿潤気候]]
[[no:Fuktig subtropisk klima]]
[[nn:Fuktig subtropisk klima]]
[[ru:Гумидный климат]]
[[tr:Türkiye'de Karadeniz İklimi]]