Addition Climate Subdivisions

World Köppen map

Köppen further divided each major divisions (A, B, C, D, E, F, H) into smaller groups based upon precipitation and temperature patterns. These subcategories are as follows:

Second letter add additional divisions based on precipitation pattern

  • f - wet year-round
  • s - dry summer season
  • w - dry winter season
  • m - monsoon

Third letter (lower case) add additional divisions based in temperature pattern

  • a - hot summer
  • b - warm summer
  • c - cool summer
  • d - very cold winters

The complete Köppen climates

Af Tropical rainforest No dry season. The driest month has at least 2.40" (61 mm) of rain. Rainfall is generally evenly distributed throughout the year. All average monthly temperatures are greater than 64°F (18°C).
Am Tropical monsoonal Pronounced wet season. Short dry season. There are one or more months with less than 2.40" (61 mm). All average monthly temperatures are greater than 64°F (18°C). Highest annual temperature occurs just prior to the rainy season.
Aw Tropical savanna Winter dry season. There are more than two months with less than 2.40" (61 mm). All average monthly temperatures are greater than 64°F (18°C).
BSh Subtropical steppe Low-latitude dry. Evaporation exceeds precipitation on average but is less than potential evaporation. Average temperature is more than 64°F (18°C).
BSk Mid-latitude steppe Mid-latitude dry. Evaporation exceeds precipitation on average but is less than potential evaporation. Average temperature is less than 64°F (18°C).
BWh Subtropical desert Low-latitude desert. Evaporation exceeds precipitation on average but is less than half potential evaporation. Average temperature is more than 64°F (18°C). Frost is absent or infrequent.
BWk Mid-latitude desert Mid-latitude desert. Evaporation exceeds precipitation on average but is less than half potential evaporation. Average temperature is less than 64°F (18°C). Winter has below freezing temperatures.
Cfa Humid subtropical Mild with no dry season, hot summer. Average temperature of warmest months are over 72°F (22°C). Average temperature of coldest month is under 64°F (18°C). Year around rainfall but highly variable.
Cfb Marine west coast Mild with no dry season, warm summer. Average temperature of all months is lower than 72°F (22°C). At least four months with average temperatures over 50°F (10°C). Year around equally spread rainfall.
Cfc Marine west coast Mild with no dry season, cool summer. Average temperature of all months is lower than 72°F (22°C). There are one to three months with average temperatures over 50°F (10°C). Year around equally spread rainfall.
Csa Mediterranean Mild with dry, hot summer. Warmest month has average temperature more than 72°F (22°C). At least four months with average temperatures over 50°F (10°C). Frost danger in winter. At least three times as much precipitation during wettest winter months as in the driest summer month.
Csb Mediterranean Mild with cool, dry summer. No month with average temperature of warmest months are over 72°F (22°C). At least four months with average temperatures over 50°F (10°C). Frost danger in winter. At least three times as much precipitation during wettest winter months as in the driest summer month.
Cwa Humid subtropical Mild with dry winter, hot summer
Dfa Humid continental Humid with hot summer
Dfb Humid continental Humid with severe winter, no dry season, warm summer
Dfc Subarctic Severe winter, no dry season, cool summer
Dfd Subarctic Severe, very cold winter, no dry season, cool summer
Dwa Humid continental Humid with severe, dry winter, hot summer
Dwb Humid continental Humid with severe, dry winter, warm summer
Dwc Subarctic Severe, dry winter, cool summer
Dwd Subarctic Severe, very cold and dry winter, cool summer
ET Tundra Polar tundra, no true summer
EF Ice Cap Perennial ice
H Complex zone. Can encompass any of the above classifications due to the mountainous terrain.

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