Köppen climate classification
The Köppen climate classification divides climates into five main climate groups, with each group being divided based on seasonal precipitation and temperature patterns. The five main groups are "A" (tropical), "B" (dry), "C" (temperate), "D" (continental), and "E" (polar). Each group and subgroup is represented by a letter. All climates are assigned a main group (the first letter). All climates except for those in the "E" group are assigned a seasonal precipitation subgroup (the second letter). For example, "Af" indicates a tropical rainforest climate. The system assigns a temperature subgroup for all groups other than those in the "A" group, indicated by the third letter for climates in "B", "C", and "D", and the second letter for climates in "E". For example, "Cfb" indicates an oceanic climate with warm summers as indicated by the ending "b". Climates are classified based on specific criteria unique to each climate type.
Oceanic climate
It typically lacks a dry season, as precipitation is more evenly dispersed throughout the year. It is the predominant climate type across much of Western Europe including the United Kingdom, the Pacific Northwest region of the United States and Canada, portions of central Mexico, southwestern South America, southeastern Australia including Tasmania, and New Zealand, as well as isolated locations elsewhere. Oceanic climates are generally characterised by a narrower annual range of temperatures than in other places at a comparable latitude, and generally do not have the extremely dry summers of Mediterranean climates or the hot summers of humid subtropical. Oceanic climates are most dominant in Europe, where they spread much farther inland than in other continents.