- Oceanic climate
An oceanic climate, also called marine west coast climate, maritime climate, Cascadian climate and British climate for Köppen climate classification Cfb and subtropical highland for Köppen Cfb or Cwb, is a type of climate typically found along the west coasts at the middle latitudes of some of the world's continents. This climate generally features warm, but not hot summers and cool, but not cold winters, with a narrow annual temperature range. It typically lacks a dry season, as precipitation is more evenly dispersed through the year. It is the predominant climate type across much of Europe, coastal northwestern North America, portions of southern South America and Africa, southeast Australia, New Zealand, as well as isolated locations elsewhere.
Climates near the ocean generally have warm (but not hot) summers, and cool (but not cold) winters. They are characterized by a narrower annual range of temperatures than are encountered in other places at a comparable latitude, and generally do not have the extremely dry summers of Mediterranean climates. Oceanic climates are most dominant in Europe, where they spread much farther inland than in other continents.
Similar climates in thermal range are also found in tropical highlands even at considerable distance from any coastline. Generally, they fall into Köppen climate classification Cfb or Cwb. The narrow range of temperatures results from the slight thermal range of temperatures between seasons characteristic of tropical lowlands. Altitudes are high enough that some places have at least one month cooler than 18 °C (64 °F) and do not qualify for grouping in the true tropical climates. This variation of the oceanic climate is termed “subtropical highland climate”. Unlike the norm in true oceanic climates, subtropical highland climates may have a marked winter drought. Agricultural potential in both oceanic climates and subtropical highland climates is similar.
Precipitation is both adequate and reliable throughout the year in oceanic climates, except in certain tropical highland areas, which would have tropical or humid subtropical climates (with a dry season in winter) if not for the high altitude making them cooler (Koppen Cwb). Under some variations of the Koeppen classification system, parts of the Pacific Northwest and south-central Chile are sometimes considered as having a Mediterranean climate (Koppen "Csb") due to a drying trend in the summer. However despite the "Csb" designation, these areas are generally considered oceanic as opposed to "Mediterranean".
In most areas with an oceanic climate, for the majority of the year precipitation comes in the form of rain. However during the winter, despite its C classification, the majority of areas with this climate see some snowfall annually. Outside of Australia, South Africa and tropical highland locations, most areas with an oceanic climate experiences at least one snowstorm per year. In the poleward locations of the oceanic climate zone (“subpolar oceanic climates”, described in greater detail below), snowfall is more frequent and commonplace.
Overall temperature characteristics vary among oceanic climates; those at the lowest latitudes are nearly subtropical from a thermal standpoint, but more commonly a mesothermal regime prevails, with cool, but not cold, winters and warm, but not hot, summers. Summers are also cooler (often much cooler) than in areas with a humid subtropical climate. Average temperature of warmest month must be less than 22 °C (72 °F) and that of the coldest month warmer than −3 °C (27 °F) although American scientists prefer 0 °C (32 °F) in the coldest month. Poleward of the latter is a zone of the aforementioned subpolar oceanic climate (Köppen Cfc), with long but relatively mild winters and cool and short summers (average temperatures of at least 10 °C (50 °F) for one to three months). Examples of this climate include parts of coastal Iceland in the Northern Hemisphere and extreme southern Chile and Argentina in the Southern Hemisphere.
London Climate chart (explanation) J F M A M J J A S O N D5282348242114451454717853201138231447231357201162158521155493 Average max. and min. temperatures in °C Precipitation totals in mm Source:  Imperial conversion J F M A M J J A S O N D246361.347361.752391.858411.963462.168521.573561.973562.268522.459462.152412.14838 Average max. and min. temperatures in °F Precipitation totals in inches
The British Isles experience a typically maritime climate, with prevailing south-westerly winds from the Atlantic Ocean. The annual average temperature range in the British Isles is only about 14 °C (25 °F). Although the west coast of Alaska experiences a maritime climate, the absence of an equally significant warm Pacific current in the upper-mid latitudes means that these regions are generally colder in winter, with more precipitation falling as snow. Typical oceanic climates are also found in the Netherlands, Belgium, most of France, western Germany, northern Spain, etc.
All mid-latitude oceanic climates are classified as humid. Some rainshadow climates with thermal régimes similar to those of oceanic climates but steppe-like (BSk) or even desert-like (BWk) scarcity of precipitation include lowland valleys of Washington and Oregon to the east of the Cascade Range, Patagonia in southern Argentina, and the Atacama Desert in northern Chile. Another example are coastal areas in southeast Western Australia.
Under Koeppen-Geiger, many areas generally considered to have Oceanic climates are classified as cool summer, dry-summer subtropical (Csb). These areas are not usually associated with a typical Mediterranean climate, and include much of the Pacific Northwest, southern Chile, parts of west-central Argentina, and northwest of the Iberian Peninsula. Many of these areas would be classified Oceanic (Cfb), except dry-summer patterns meet Koeppen's Cs thresholds, and cities such as Concepción, Chile; Seattle, Washington; Portland, Oregon; Victoria, British Columbia; and Vancouver, British Columbia can be classified as Csb.
The only noteworthy area of Maritime Climate at or near sea-level within Africa is in South Africa from Mossel Bay on the Western Cape coast to Plettenberg Bay, with additional pockets of this climate inland of the Eastern Cape and KwaZulu-Natal coast. Interior southern Africa, elevated portions of eastern Africa, and Mozambique also share this climate type. It is usually warm most of the year with no pronounced rainy season, but slightly more rain in autumn and spring. The only significant areas where this climate is found in Asia is on the Black Sea coast in northern Turkey, in small pockets along or near the Caspian Sea in Azerbaijan and in small pockets along or near the Tsugaru Strait in northern Japan. The oceanic climate is prevalent in a good portion of western Europe and the European part of northern Turkey. The oceanic climate is prevalent in the more southerly locations of Oceania. A mild Maritime climate is in existence in New Zealand, the island of Tasmania, Australia, southern parts of Victoria and New South Wales, Australia. It can also be found along the western areas of the south coast of Western Australia. The oceanic climate is found in isolated pockets in South America. It exists in central Argentina, southern Chile and parts of Brazil, Ecuador and Colombia. The oceanic climate exists in an arc spreading across the north-western coast of North America, largely in the Pacific Northwest. It includes the western parts of Washington and Oregon, the Alaskan panhandle, western portions of British Columbia, and north-western California. A significant portion of oceanic climate exhibited in North America features a drying trend in the summer, thus falling under the Marine West Coast subcategory explained below.
Subtropical highland variety (Cwb)
Mexico City Climate chart (explanation) J F M A M J J A S O N D112164.3237102692627115627121352512175231216923121452212672210122286217 Average max. and min. temperatures in °C Precipitation totals in mm Source: WMO Imperial conversion J F M A M J J A S O N D0.470420.273450.47849180512.280535.376546.973536.774535.772532.672500.571460.26944 Average max. and min. temperatures in °F Precipitation totals in inches
The Subtropical Highland variety of the oceanic climate exists in elevated portions of the world that are either within the tropics or subtropics, though it is typically found in mountainous locations in some tropical countries. Despite the latitude, the higher altitudes of these regions mean that the climate tends to share characteristics with oceanic climates, though it also tends to experience noticeably drier weather during the "low-sun" season.
In locations outside the tropics, other than the drying trend in the winter, Subtropical Highland climates tend to be essentially identical to an oceanic climate, with mild summers and noticeably cooler winters plus, in some instances, some snowfall. In the tropics, a Subtropical Highland climate tends to feature spring-like weather year-round. Temperatures here remain relatively constant throughout the year and snowfall is seldom seen. Areas with this climate feature monthly averages below 22 °C (72 °F) but above −3 °C (27 °F) (or 0 °C (32 °F) using American standards). At least one month's average temperature is below 18 °C (64 °F). Without the elevation, many of these regions would likely feature either tropical or humid subtropical climates. These regions usually carry a Cwb or Cfb designation, though very small areas in Yunnan, Sichuan and parts of Argentina and Bolivia may have summers sufficiently short to be Cwc with fewer than four months over 10 °C (50 °F), though no records exist for such stations.
This type of climate exists in parts of east, south and south-eastern Africa, some mountainous areas across southern Europe, sections of mountainous Latin America, some mountainous areas across Southeast Asia, higher elevations of the southern Appalachians, and parts of the Himalayas. It also occurs in a few areas of Australia, although average high temperatures during summers there tend to be higher and the climate drier than is typical of Subtropical Highland Climates, with maximums sometimes exceeding 40 °C (104 °F).
Subpolar variety (Cfc)
Reykjavík Climate chart (explanation) J F M A M J J A S O N D762−3723−2823−258604494501275213862138671058672733−1792−3 Average max. and min. temperatures in °C Precipitation totals in mm Source: WMO Imperial conversion J F M A M J J A S O N D335272.837283.238282.342331.7493825344256472.455462.650413.444362.938303.13627 Average max. and min. temperatures in °F Precipitation totals in inches
Areas with Subpolar Oceanic climates feature an oceanic climate but are usually located closer to Polar regions. As a result of its location, these regions tend to be on the cool end of oceanic climates. Snowfall tends to be more common here than in other oceanic climates. Subpolar Oceanic climates are less prone to temperature extremes than Subarctic climates or Humid continental climates, featuring milder winters than these climates. Subpolar Oceanic climates feature only one to three months of average monthly temperatures that are at least 10°C (50°F). Like oceanic climates, none of its average monthly temperatures fall below -3°C (26.6°F). It typically carries a Cfc designation. This variant of an oceanic climate is found in parts of coastal Iceland, the Faroe Islands, small sections of the Scottish Highlands, northwestern coastal areas of Norway reaching to 70°N on some islands, uplands near the coast of southwestern Norway, southern islands of Alaska and northern parts of the Alaskan Panhandle, the far south of Chile and Argentina, and a few highland areas of Tasmania and the Australian Alps. The classifications used to this regime are Cfc.
Seattle Climate chart (explanation) J F M A M J J A S O N D130821061039512466156451883821112024132624134121118115816010414382 Average max. and min. temperatures in °C Precipitation totals in mm Source:  Imperial conversion J F M A M J J A S O N D5.146364.249373.853392.658421.864471.570520.87555176561.670523.260466.351405.64636 Average max. and min. temperatures in °F Precipitation totals in inches
Despite the fact that dry summers is a feature which differentiates Csb areas from oceanic climates, some areas of Csb climate are typically considered "Oceanic" as opposed to "Mediterranean" (see Mediterranean climate). Technically, this version of the Oceanic climate meets Koppen's minimum precipitation threshold limit of 30 millimetres (1.2 in) (or 40 millimetres (1.6 in) under Koppen-Geiger), resulting in a Csb designation. Nevertheless, due to the higher annual accumulation of precipitation and generally cloudier conditions that these regions experiences in comparison to other areas with Csb climates, scientists such as Trewartha consider this climate oceanic (Do, which is an oceanic climate classification under the Trewartha system). This is especially the case in the Pacific Northwest region of the United States and Canada, some sections of coastal Chile, in Galicia in northwestern Spain and in northern Portugal, where conditions are wetter and generally cloudier during the course of the year than typical Csb climates. Nevertheless, those regions have several Mediterranean features :
- Greater annual hours of sunshine than the typical oceanic domain, especially during the drier summer months. For example, La Coruna or Seattle have at least 2000 hours of sunshine, while the values of the typical Cfb regions are far below (almost always below 2000 hours).
- Vegetation which is partially adapted to xeric conditions. So the cork oak, a typically acidophilus Mediterranean species, and which is widely distributed in Portugal and in southern-half of Galicia. In contrast, beech or birch, widely distributed in the Cfb area, are not common in Iberia, mostly confined to the Pyrenees and the Cantabrian mountains. In addition, Garry oak, typical of California, can be found as far north as Vancouver Island. Douglas fir which is the typical species of the Pacific Northwestern forests, is very well adapted to the summer drought.
- Forest fires are regular in those regions due to the summer-drought.
- Climate classification
- Temperate climate
- Humid subtropical climate
- Subtropical climate
- Continental climate
- Polar climate
- ^ Lauren Springer Ogden (2008). Plant-Driven Design. Timber Press. p. 78. ISBN 9780881928778.
- ^ Climate (2009-06-19). "Oceanic Climate". http://www.meteorologyclimate.com/Oceanic-climate.htm. Retrieved 2011-01-30.
- ^ M. Pidwirny (2006). Fundamentals of Physical Geography: Climate Classification and Climatic Regions of the World (2 ed.). http://www.physicalgeography.net/fundamentals/7v.html. Retrieved 2011-01-30.
- ^ a b c Tom L. McKnight and Darrel Hess (2000). Climate Zones and Types: The Köppen System. Physical Geography: A Landscape Appreciation. Prentice Hall. pp. 226–235. ISBN 0-13-020263-0.
- ^ National Climatic Data Center. "Cloudiness – Mean Number of Days". National Oceanic and Atmospheric Administration. http://lwf.ncdc.noaa.gov/oa/climate/online/ccd/cldy.html. Retrieved November 7, 2010.
- ^ Regionally mapped climate averages
- ^ a b M. C. Peel, B. L. Finlayson, and T. A. McMahon (2007-10-11). "Updated world map of the Köppen-Geiger climate classification". Hydrology and Earth System Sciences 11: 1638–1643. http://hal.archives-ouvertes.fr/docs/00/30/50/98/PDF/hess-11-1633-2007.pdf. Retrieved 2011-01-30.
- ^ [hal.archives-ouvertes.fr/docs/00/29/88/18/PDF/hessd-4-439-2007.pdf]
- ^ Bureau of Meteorology (2011). "Climate of Canberra Area". Commonwealth of Australia. http://www.bom.gov.au/nsw/canberra/climate.shtml. Retrieved 2011-01-30.
- ^ http://www.yr.no/place/Norway/Finnmark/Hasvik/Hasvik~320932/statistics.html
- ^ Tapper, Andrew; Tapper, Nigel (1996). Gray, Kathleen. ed. The weather and climate of Australia and New Zealand (First ed.). Melbourne, Australia: Oxford University Press. p. 300. ISBN 0195533933.
- ^ http://www.fao.org/docrep/006/ad652e/ad652e33.gif
- ^ http://www.aemet.es/es/elclima/datosclimatologicos/valoresclimatologicos?l=1387&k=gal
- ^ http://climat.meteofrance.com/chgt_climat2/climat_france?73928.path=climatstationn%252F29075001
- ^ http://iniagis.inia.es/Quercus%20suber/
- ^ http://iniagis.inia.es/Fagus%20sylvatica/
- ^ http://iniagis.inia.es/Betula%20pendula/
- ^ http://treephys.oxfordjournals.org/content/22/15-16/1107.full.pdf
- ^ http://www.iberianature.com/material/fire.html.
- ^ http://www.dnr.wa.gov/SiteCollectionImages/Places/rp_fire_ifplmap.jpg
- University of Wisconsin–Stevens Point: Marine (Humid) West Coast Climate
- EPIC Data Collection On-line ocean observational data collection
- NOAA In-situ Ocean Data Viewer Plot and download ocean observations
Class A Class B Class C Class D Class E
Wikimedia Foundation. 2010.
Look at other dictionaries:
Climate of Spain — Climate of the Iberian Peninsula according to the Köppen Climate Classification. Spanish State Meteorological Agency Agencia Estatal de Meteorología and Portuguese Meteorological Institute Instituto de Meteorologia. … Wikipedia
Climate of Oregon — Climate zones of the Continental United States. Oregon s climate varies greatly from the western and eastern regions of the state. An oceanic climate (also called west coast marine climate ) predominates in Western Oregon, and a much drier semi… … Wikipedia
Climate of Alaska — Natural colour satellite image showing thin plumes of beige dust blowing off the Alaskan coast … Wikipedia
Climate — For other uses, see Climate (disambiguation). Worldwide Climate Classifications Climate encompasses the statistics of temperature … Wikipedia
Climate of the Drôme department — The climate of the Drôme department is in a zone of transition between the oceanic climate of Lyon, the continental climate of the north and the Mediterranean climate of Provence to the south. In the Rhône valley, the meeting of mild and humid… … Wikipedia
Climate of the United States — For change, see Climate change in the United States. Climate zones of the Continental United States. The United States includes a wide variety of climate types due to its large size, range of geographic features, and non contiguous arrangement.… … Wikipedia
Climate of south-west England — The Met Office region of south west England, shown within England. The climate of south west England is classed as oceanic (Cfb) according to the K … Wikipedia
Climate of Italy — Italy has a variety of climate systems. The inland northern areas of Italy (for example Turin, Milan, and Bologna) have a Humid subtropical climate (Köppen climate classification Cfa), while the coastal areas of Liguria and the peninsula south of … Wikipedia
Climate of Europe — Biomes of Europe and surrounding regions: tundra alpine tundra taiga … Wikipedia
Climate of Turkey — The coastal areas of Turkey bordering the Aegean Sea and the Mediterranean Sea have a temperate Mediterranean climate, with hot, dry summers and mild to cool, wet winters. The coastal areas of Turkey bordering the Black Sea have a temperate… … Wikipedia