An oceanic climate (also called marine west coast climate, maritime climate, subtropical highland and British climate) is the climate typically found along the west coasts at the middle latitudes of all the world's continents, and in southeastern Australia. Climates near the ocean have moderately cool summers and comparatively cool winters, they are generally characterized by a narrower annual range of temperatures than are encountered in other places at a comparable latitude, and do not have the extremely dry summers of Mediterranean climates.

Similar climates, at least 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 not from proximity to a coastline but instead to the slight thermal range of temperatures between seasons characteristic of tropical lowlands; altitudes are high enough that somes places have at least one month cooler than 18 °C and do not qualify for grouping in the true tropical climates. Unlike the norm in true oceanic climates, these moist highland tropical climates may have a marked winter drought, as in Mexico City. Agricultural potential in both oceanic climates and moist tropical highland climates are practically identical. These climates are most dominant in Europe, where it spreads much farther inland than in other continents.

Precipitation

Precipitation is both adequate and reliable at all times of the year in oceanic climates. Except in certain tropical highland areas, which would have tropical savanna or steppe 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.

Temperature

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 in the coldest month. Poleward of the latter is a zone of subpolar oceanic climate (Köppen Cfc), with long but relatively mild winters (coldest month warmer than -3 or 0) and cool summers and a short summer season (average temperature at least 10 °C or 50 °F) of less than four months; examples of this climate include parts of coastal Iceland in the Northern Hemisphere and extreme southern Chile in the Southern Hemisphere (the fact that this form of climate exists in both hemispheres rules out the use of such terms as subarctic or boreal to denote it; even though these terms are used to refer to climates characterized by short summers, they are also synonyms for "northern" and therefore inappropriate).

Additional information

The British Isles experiences 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 24 °C. 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.

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.

Regions/Cities with Oceanic Climates

Europe

Oceanic climate is prevalent in a good portion of Europe, particularly Western and Northern Europe. Its exists in northern and western France, the Netherlands, Belgium, western and northwestern Germany, western Switzerland (lowland areas), northern Spain (so-called "Green Spain": Galicia, Asturias, Basque Country...), northern extreme of Portugal,southwest Norway, parts of Denmark, Ireland, Scotland, Wales, England, and northern Turkey,

Oceania

Maritime Climates are prevalent in the more southerly locations of this region. 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

South America

Oceanic Climates are found in isolated pockets in South America. It exists in Central Argentina, Southern Chile and parts of Brazil.

North America

Oceanic Climate primarily exists along the coast of the Pacific Northwest in North America. It exists in the western parts of Oregon, Washington and the mildest coastal areas of the Alaskan panhandle in the (U.S.A.) and the western portions of British Columbia (Canada) . It also exists in extreme Northwest California (U.S.A.).

Notable Cities with Oceanic Climates

London, England Paris, France Frankfurt, Germany Berlin, Germany Amsterdam, Netherlands Bordeaux, France Birmingham, England Dublin, Ireland Edinburgh, Scotland Glasgow, Scotland Copenhagen, Denmark Bilbao, Spain Vigo, Spain Brussels, Belgium

Rize, Turkey Samsun, Turkey Vancouver, Canada Victoria, Canada Seattle, USA Portland , USA Valdivia, Chile Mar del Plata, Argentina Bahía Blanca, Argentina Melbourne, Australia Hobart, Australia Auckland, New Zealand Wellington, New Zealand

Regions/Cities with Subtropical Highland Climates

The Subtropical Highland variety of this climate exists in elevated portions of the world that are either within the tropics or subtropics though they are typically found in mountainous locations in some tropical countries. Despite the latitude, due to the higher altitudes of these regions, they tend to share several characteristics with Oceanic Climates, though they also tend to be drier. In locations near the equator, areas with the subtropical highland variety of this climate typically features spring-like weather year-round. Temperatures remain relatively constant throughout the year, with monthly averages for all 12 months below 22°C (72°F) but above -3°C (26.6°F) (or 0°C (32°F) using American standards). Also, at least one month's average temperature is below 18°C (64.4°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. . It exists in parts of east, south and south-eastern Africa, some mountainous areas across southern Europe, sections of mountainous Latin America, higher elevations of the southern Appalachians, and parts of the Himalayas.

Notable Cities with Subtropical Highland Climates

• Mexico City, Mexico
• Puebla, Mexico
• Guatemala City, Guatemala
• Antananarivo, Madagascar
• Johannesburg, South Africa
• Addis Ababa, Ethiopia
• Nairobi, Kenya
• Bogotá, Colombia
• La Paz, Bolivia
• Quito, Ecuador
• Curitiba, Brazil
• Gangtok, India
• Boone , USA

Regions/Cities with Subpolar Oceanic Climates

These are regions that feature an oceanic climate but are usually located closer to Polar Regions. As a result of its location, these regions tend to be somewhat cooler than other Oceanic Climates. Still, Subpolar Oceanic Climates are less prone to temperature extremes than Subarctic climates, featuring much milder winters. It typically carries a “Cfc” designation. This variant of Oceanic Climates are found in parts of coastal Iceland, Faroe Islands, northwestern coastal areas of Norway reaching to 70°N on some islands, southern islands of Alaska and parts of the Alaskan Panhandle, the far south of Chile and Argentina and Mountainous areas of Europe, including the Scottish Highlands and uplands near the coast of southwestern Norway.

Notable cities with Subpolar Oceanic Climates

• Reykjavik, Iceland
• Vestmannaeyjar, Iceland
• Harstad, Norway
• Thorshavn, Faroe Islands
• Unalaska, USA (also known as Dutch Harbor)
• Ushuaia, Argentina

Isotherm boundary to Dfb climate

The 0 °C (32 °F) isotherm (freeze line) or the -3 °C (26.6 °F) isotherms (persistent snow line) are the possible lines dividing the oceanic and the warm summer humid continental (Dfb) climates, in between which are the following regions:

• Eastern Germany
• Luxembourg
• Liechtenstein
• Western Poland
• Eastern Switzerland and parts of Austria
• Western Alps between 700 and 1000 meters.
• Central and Eastern Alps between 500 and 800 meters.
• Southern Sweden
• Fjord areas inland from the coast of southwest Norway and parts of the southeast coast of Norway
• Much of Denmark
• Southern coastal areas of the Alaskan Panhandle
• Most of the Czech Republic
• Parts of western Slovakia
• Northwest Romania
• Most of Hungary
• Most of Slovenia
• Parts of Bosnia-Herzegovina
• Mountainous areas across southern Europe
• Himalayas
• Some southern coastal areas of New England
• Parts of the southern Appalachians at the higher elevations

Charts of Selected Cities with Oceanic Climates

Northern hemisphere

Southern hemisphere

See also

• Temperate climate
• Humid subtropical climate
• Mediterranean climate
• Subtropical climate
• Continental climate
• Polar climate

References

External links

• 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
• http://www.ace.mmu.ac.uk/eae/Climate/Older/Maritime_Climate.html