Trewartha climate classification

Climate classification system World map of the Trewartha climate classification, with 1991-2020 normals Ar: Tropical Wet Am: Tropical Monsoon Aw: Tropical Dry-Winter As: Tropical Dry-Summer Bw: Desert or Arid Bs: Steppe or Semiarid Cs: Subtropical Dry Summer Cw: Subtropical Monsoon Cf: Subtropical Humid Do: Temperate Oceanic Dc: Temperate Continental Eo: Boreal Oceanic Ec: Boreal Continental Ft: Tundra Fi: Ice Cap The Trewartha climate classification (TCC), or the Köppen–Trewartha climate classification (KTC), is a climate classification system first published by American geographer Glenn Thomas Trewartha in 1966. It is a modified version of the Köppen–Geiger system, created to answer some of its deficiencies. The Trewartha system attempts to redefine the middle latitudes to be closer to vegetation zoning and genetic climate systems. Scheme Trewartha's modifications to the 1884 Köppen climate system sought to reclass the middle latitudes into three groups, according to how many months have a mean temperature of 10 °C (50 °F) or higher: C (subtropical)—8 or more months; D (temperate)—4 to 7 months; E (boreal)—1 to 3 months. The tropical climates and polar climates rem