Köppen's climate classification system, developed by Wladimir Köppen, is one of the most widely used systems, categorizing climates based on vegetation distribution, which in turn is determined by temperature and precipitation. The system uses a series of letters to denote major climate groups and subgroups. Its latitudinal distribution reflects the primary control of solar radiation and atmospheric circulation patterns.

General Latitudinal Distribution:

1. Tropical Climates (Group A): These climates are found near the equator, roughly between 15°N and 15°S latitude, extending sometimes to 25°N/S. They are characterized by consistently high temperatures (mean monthly temperature above 18°C) and significant precipitation. There are three main types:

   • Af (Tropical Rainforest): Closest to the equator, with high rainfall year-round (e.g., Amazon Basin, Congo Basin, parts of Southeast Asia).
   • Am (Tropical Monsoon): Experiences a distinct wet and dry season, influenced by monsoon winds (e.g., Indian subcontinent, parts of Southeast Asia).
   • Aw (Tropical Savanna): Further poleward from Af, with a more pronounced dry season (e.g., Central Africa, parts of South America, Northern Australia).

2. Dry Climates (Group B): These climates are typically found poleward of the tropical wet climates, roughly between 15° and 30° latitude in both hemispheres, often extending into continental interiors. They are characterized by low precipitation and high evaporation rates. They are often associated with the subtropical high-pressure belts.

   • BWh (Hot Desert): Extremely arid and hot (e.g., Sahara, Arabian Desert, Atacama Desert).
   • BWk (Cold Desert): Arid but with colder winters (e.g., Gobi Desert, Patagonian Desert).
   • BSh (Hot Steppe): Semi-arid, bordering hot deserts (e.g., Sahel region).
   • BSk (Cold Steppe): Semi-arid, bordering cold deserts or humid mid-latitude climates (e.g., Great Plains of North America, Central Asia).

3. Temperate/Mesothermal Climates (Group C): Located in the mid-latitudes, generally between 30° and 50° latitude, these climates experience distinct seasons with warm/hot summers and mild winters. They are influenced by westerly winds and cyclonic activity.

   • Cfa/Cwa (Humid Subtropical): Hot, humid summers and mild winters, found on the eastern sides of continents (e.g., Southeastern USA, Eastern China).
   • Cfb/Cfc (Marine West Coast): Mild summers and cool, but not cold, winters with year-round precipitation, found on the western sides of continents (e.g., Western Europe, Pacific Northwest of North America).
   • Csa/Csb (Mediterranean): Hot, dry summers and mild, wet winters, found on the western sides of continents (e.g., Mediterranean Basin, California, parts of Chile).

4. Continental/Microthermal Climates (Group D): Found in the higher mid-latitudes, typically between 40° and 70° latitude, primarily in the Northern Hemisphere due to large continental landmasses. They are characterized by significant seasonal temperature variations, with cold winters and warm/hot summers.

   • Dfa/Dwa (Humid Continental): Hot summers, cold winters (e.g., Midwestern USA, Eastern Europe).
   • Dfb/Dwb (Humid Continental): Warm summers, cold winters (e.g., New England, parts of Russia).
   • Dfc/Dwc/Dfd/Dwd (Subarctic/Boreal): Short, cool summers and very cold, long winters (e.g., Siberia, interior Canada).

5. Polar Climates (Group E): Located at high latitudes, generally above 60° latitude, characterized by extremely cold temperatures and the absence of a true summer.

   • ET (Tundra): Mean temperature of the warmest month is between 0°C and 10°C, supporting low-growing vegetation (e.g., Arctic coasts, high mountain tops).
   • EF (Ice Cap): Mean temperature of all months is below 0°C, covered by permanent ice and snow (e.g., Greenland, Antarctica).

6. Highland Climates (Group H): While not strictly latitudinal, this category accounts for the significant variations in climate due to altitude in mountainous regions, which can mimic the zonation seen from the equator to the poles (e.g., Himalayas, Andes, Rockies). Temperature decreases with altitude, leading to a rapid succession of climate types.

This latitudinal arrangement reflects the decreasing intensity of solar radiation from the equator to the poles, modified by factors like continental size, ocean currents, mountain ranges, and atmospheric pressure systems.