The 5 Major Climate Zones of Earth: Köppen Classification Simplified

The Köppen-Geiger system organizes Earth's climates into five primary groups (A–E), each with distinct temperature/precipitation patterns. Here's the practical breakdown.

A — Tropical (Equatorial: 0–25° lat)

• Core trait: All months ≥18°C (64°F); no winter
• Subtypes:
  • Af — Rainforest: >60 mm rain every month (Amazon, Congo, SE Asia)
  • Am — Monsoon: Short dry season, heavy wet (India, N. Australia)
  • Aw/As — Savanna: Distinct wet/dry (Serengeti, Cerrado, N. Australia)

B — Dry (Arid/Semi-Arid)

• Core trait: Precipitation < potential evaporation
• Subtypes:
  • BW — Desert (Sahara, Atacama, Arabian, Mojave)
  • BS — Semi-arid/Steppe (Great Plains, Patagonia, Central Asia)
  • h/k — Hot (subtropical) / Cold (mid-latitude) variants

C — Temperate (Mid-Latitudes: 25–50°)

• Core trait: Coldest month: −3°C to 18°C (27–64°F); ≥4 months ≥10°C
• Subtypes:
  • Cfa — Humid subtropical: Hot humid summers, mild winters (SE US, E. China, Argentina)
  • Cfb — Oceanic: Mild year-round, no dry season (UK, NW Europe, NZ, Chile)
  • Csa/Csb — Mediterranean: Dry summers, wet winters (CA, Chile, Med Basin, SW Australia)

D — Continental (High Mid-Latitudes: 40–65°)

• Core trait: Coldest month <−3°C (27°F); ≥4 months ≥10°C
• Subtypes:
  • Dfa/Dfb — Humid continental: Hot/warm summers, cold winters (NE US, E. Europe, NE Asia)
  • Dwa/Dwb — Monsoon-influenced (Manchuria, Korea)
  • Dfc/Dfd — Subarctic: Short cool summers, brutal winters (Siberia, N. Canada, Alaska)

E — Polar (High Latitudes: >65°)

• Core trait: All months <10°C (50°F); no true summer
• Subtypes:
  • ET — Tundra: 0–10°C warmest month (Arctic coast, high mountains)
  • EF — Ice Cap: All months <0°C (Antarctica, Greenland interior)

Highland (H) — Not a Zone, A Modifier

Elevation creates climate islands: temperature drops ~6.5°C/km. A tropical mountain can host A→C→D→E zones vertically.

Key Insight: These zones explain biomes, agriculture, architecture, energy demand, and culture. Climate isn't weather—it's the statistical envelope within which weather varies.