Oceanic climate

An oceanic climate (also known as marine, west coast and maritime) is the climate typical of the west coasts at the middle latitudes of continents, and generally features warm (but not hot) summers and cool (but not cold) winters, with a relatively narrow annual temperature range. It typically lacks a dry season, as precipitation is more evenly dispersed throughout the year. It is the predominant climate type across much of Northern Western Europe, parts of the Appalachians, portions of southwestern South America and small areas of Africa, in southeast Australia, and New Zealand as well as isolated locations elsewhere.

Under the Köppen climate classification, the typical zone associated with the Oceanic climate is Cfb, although it includes subtropical highland zones not usually associated with marine climates. Often, parts of the Csb Mediterranean or Dry-Summer subtropical zones are not associated with a typical Mediterranean climate, and would be classified as Temperate Oceanic (Cfb), except dry-summer patterns meet Köppen's minimum Cs thresholds. Other climate classification systems, such as Trewartha climate classification, place these areas firmly in the Oceanic zone (Do).

Climate categories in viticulture

In viticulture, the climates of wine regions are categorised based on the overall characteristics of the area's climate during the growing season. While variations in macroclimate are acknowledged, the climates of most wine regions are categorised (somewhat loosely based on the Köppen climate classification) as being part of a Mediterranean (for example Tuscany), maritime (ex: Bordeaux) or continental climate (ex: Columbia Valley). The majority of the world's premium wine production takes place in one of these three climate categories in locations between the 30th parallel and 50th parallel in both the northern and southern hemisphere. While viticulture does exist in some tropical climates, most notably Brazil, the amount of quality wine production in those areas is so small that the climate effect has not been as extensively studied as other categories.

Influence of climate on viticulture

Beyond establishing whether or not viticulture can even be sustained in an area, the climatic influences of a particular area goes a long way in influencing the type of grape varieties grown in a region and the type of viticultural practices that will be used. The presence of adequate sun, heat and water are all vital to the healthy growth and development of grapevines during the growing season. Additionally, continuing research has shed more light on the influence of dormancy that occurs after harvest when the grapevine essentially shuts down and reserves its energy for the beginning of the next year's growing cycle.