Aspirant Academy

Geography

Climate Classification and Major Climate Types

Climate: Insolation, Atmospheric Circulation, Humidity, Precipitation

Paper II · Unit 3 Section 7 of 12 0 PYQs 32 min
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Climate Classification and Major Climate Types

6.1 Köppen Climate Classification

The Köppen System (developed by Wladimir Köppen, 1900; updated by Trewartha and Geiger) is the most widely used climate classification, based on temperature and precipitation patterns matched to natural vegetation.

  • All months above 18°C; high rainfall

  • Af (Tropical Rainforest): Rain every month (>60 mm); Amazon, Congo, SE Asia

  • Am (Monsoon): Short dry season; compensated by heavy monsoon rain; India's west coast

  • Aw (Tropical Savanna): Distinct dry season; Africa's savannas (Serengeti), Brazilian Cerrado, India's interior (Deccan)

  • Evaporation exceeds precipitation

  • BWh (Hot Desert): Annual rainfall <250 mm; Sahara, Arabian, Thar, Australian interior

  • BWk (Cold Desert): Low temperature + low rainfall; Gobi, Taklamakan

  • BSh (Hot Semi-Arid/Steppe): 250–500 mm rainfall; marginal zone around hot deserts (Sahel)

  • BSk (Cold Semi-Arid/Steppe): Great Plains USA, Central Asian steppes

  • Coldest month: -3°C to 18°C; at least 1 month >10°C

  • Csa/Csb (Mediterranean): Dry hot/warm summer + wet mild winter; Mediterranean Basin, California, Chile (central), SW Australia, Cape Province (South Africa). Key products: olives, grapes, citrus.

  • Cfa (Humid Subtropical): Hot humid summer + mild winter; SE USA, SE China, Brazil, India's NE coastal strip

  • Cfb (Oceanic/Marine): Mild, wet year-round; Western Europe, W coast Canada, S Chile, SE Australia

  • Coldest month: below -3°C; at least 4 months >10°C; large temperature range

  • Dfa/Dfb: Humid continental; N USA, S Canada, NE China, Russia

  • Characteristic of interior North America and Eurasia; cold winters, warm-hot summers; severe blizzards

**Group E — Polar (Frigid) — **

  • All months below 10°C; tundra or permanent ice
  • ET (Tundra): Some months briefly above 0°C; permafrost; Arctic rim (N Canada, Siberia, Greenland coast); sparse vegetation (mosses, sedges)
  • EF (Ice Cap): All months below 0°C; permanent ice; Greenland interior, Antarctica

6.2 Mediterranean Climate — Special Case (PYQ 2013 Context)

The Mediterranean climate (Csa/Csb) is distinctive because it is the only climate type with dry summers and wet winters — opposite to most other climates. This is because the subtropical high pressure belt migrates poleward in summer (blocking rain) and equatorward in winter (allowing westerlies and frontal rain to reach these regions).

Five Mediterranean Regions Globally

  1. Mediterranean Basin (Spain, France, Italy, Greece, Turkey, N Africa coasts) — namesake
  2. California (Central California south — Los Angeles, San Francisco)
  3. Central Chile (around Santiago)
  4. Southwest Australia (Perth region)
  5. Cape Province, South Africa (Cape Town region)

Key Characteristics

  • Summer: Hot, dry (30–35°C); clear blue skies; fires common (chaparral/maquis vegetation burns easily)
  • Winter: Mild, wet (10–15°C); moderate rainfall 400–800 mm/year
  • Vegetation: Sclerophyll (drought-adapted hard-leaved shrubs) — chaparral (California), maquis/garrigue (Mediterranean), fynbos (S Africa), kwongan (Australia)
  • Agriculture: Olives, grapes (wine), citrus, almonds, figs; irrigation-dependent in summer