Free Daily UPSC Mains Practice QuestionsPractice today →
Home › Subjects › Geography › Classification of World Climates
Topic 41 of 290 Free

Classification of World Climates

Geography · Learn · Prepare · Practice · Evaluate
1

Learn the Concept

All

A classification of world climates groups the Earth's many local climates into a manageable set of types with shared characteristics, so patterns can be mapped and compared. Fix the main schemes: the most widely used is Köppen's empirical classification (based on temperature, precipitation and their link to vegetation, with letter codes A–E); Thornthwaite's is a more rational scheme based on water balance (precipitation effectiveness); and Trewartha's is a modified, simplified Köppen. Each has merits and limitations, and together they organise the major climatic regions of the world.

In One Line
  • Köppen (empirical): temperature + rainfall + vegetation; groups A, B, C, D, E (+ H).
  • Thornthwaite (rational): water balance — potential evapotranspiration & moisture index.
  • Trewartha: a simplified modification of Köppen.
  • Use: maps the world's major climatic regions; each scheme has merits & limits.
Glossary (define-on-first-use)
  • Empirical classification: based on observed data (Köppen — temperature & rainfall).
  • Genetic / rational classification: based on causes or on water balance (Thornthwaite).
  • Potential Evapotranspiration (PE): the water that could evaporate & transpire given the energy available.
  • Moisture Index: Thornthwaite's measure of precipitation relative to PE (surplus vs deficit).
  • Climatic region: an area of broadly uniform climate.

1. Köppen's classification

  • Wladimir Köppen (1918) devised the most popular scheme, empirical and tied to vegetation, using letter codes. The five main groups (by a capital letter):
Köppen's five main climate groups A — Tropical (hot, every month >18°C; rainforest, savanna) B — Dry (arid/semi-arid; evaporation > precipitation; deserts, steppe) C — Warm temperate / mid-latitude (mild winters; Mediterranean, humid subtropical) D — Cold / continental (cold winters; taiga) E — Polar (coldest month <10°C; tundra, ice-cap) [H = Highland]
Fig 1 — Köppen's groups A (tropical), B (dry), C (warm temperate), D (cold), E (polar), with H for highland.
  • Sub-types add a second (small) letter for rainfall seasonality (f = no dry season, w = dry winter, s = dry summer, m = monsoon) and a third for temperature detail — e.g. Af (tropical rainforest), Aw (savanna), BWh (hot desert), Cs (Mediterranean), Cwa (humid subtropical, much of N India), Df (continental), ET (tundra).
  • Merits: simple, data-based, linked to vegetation, easy to map. Limitations: purely empirical (ignores causes/air masses), boundaries are rigid, underplays wind/pressure, and over-relies on a few thresholds.

2. Thornthwaite's classification

  • C.W. Thornthwaite (1931/1948) offered a more rational scheme based on the water balance: he introduced Potential Evapotranspiration (PE) and a Moisture Index (comparing precipitation with PE) to classify climates from perhumid to arid, plus a thermal efficiency index. Merits: scientifically grounded in moisture availability (useful for agriculture/hydrology). Limitations: complex, data-hungry, and less easy to map than Köppen.

3. Trewartha & the major climatic regions

  • G.T. Trewartha modified Köppen into a simpler, more realistic scheme, re-grouping the mid-latitude types and giving clearer criteria.
  • Whichever scheme is used, the world's major climatic regions run broadly by latitude: Equatorial (Af), Tropical monsoon (Am), Savanna (Aw), Hot desert (BWh), Mediterranean (Cs), Humid subtropical (Cfa/Cwa), Marine west-coast (Cfb), Continental (Df), Taiga, Tundra (ET) and Ice-cap (EF) — each with its own temperature, rainfall, vegetation and human activity.
SchemeBasisNature
KöppenTemperature + rainfall + vegetationEmpirical (most used)
ThornthwaiteWater balance (PE, moisture index)Rational
TrewarthaModified KöppenSimplified empirical
Key Facts to Remember
  • Köppen = empirical (temp + rainfall + vegetation); groups A (tropical), B (dry), C (warm temperate), D (cold), E (polar), H (highland).
  • Second letters: f (no dry season), w (dry winter), s (dry summer), m (monsoon).
  • Thornthwaite = rational, water-balance (PE & moisture index).
  • Trewartha = simplified Köppen.
  • Much of north India = Cwa; Thar = BWh; Kerala/NE = Am/Af.
Connect the Dots
  • Weather & climate: classifying long-term climate (previous leaf).
  • Biogeography: climate–vegetation (biomes) link (later unit).
  • Climatic regions of India (Paper II): Köppen applied to India.
  • Hydrological cycle: PE & water balance (next leaf).
2

Prepare for the Exam — Prelims

Prelims

Tested on Köppen groups & letter codes, Thornthwaite's water-balance basis, Trewartha, and Indian climate codes.

High-probability areas
  • Köppen = empirical (temp+rainfall+vegetation); A/B/C/D/E.
  • Letters: f (no dry), w (dry winter), s (dry summer), m (monsoon).
  • Af=rainforest, Aw=savanna, BWh=hot desert, Cs=Mediterranean.
  • Thornthwaite = water balance (PE, moisture index).
  • Trewartha = modified Köppen.
Common traps
  • Köppen ignores causes (empirical, not genetic).
  • B = dry climate (evaporation > precipitation).
  • Cs = dry-summer (Mediterranean).
  • North India largely Cwa; Thar = BWh.
Revision tip: Köppen (A/B/C/D/E + f/w/s/m) → Thornthwaite (water balance/PE) → Trewartha (simplified) → world regions.
2

Prepare for the Exam — Mains

Mains

Optional Paper I / GS Paper I. The examiner rewards comparing the schemes with merits/limitations.

Likely question types
  • Explain Köppen's classification and assess its merits and limitations. (15)
  • Compare the Köppen and Thornthwaite schemes. (15)
  • Discuss the basis of Thornthwaite's classification. (10)
  • Apply Köppen's scheme to India. (10)
Dimensions to cover
  • Köppen groups & codes.
  • Thornthwaite water balance.
  • Trewartha.
  • Merits/limits; Indian examples.
Value-additions
  • PE & moisture index.
  • Cwa (N India), BWh (Thar).
  • Empirical vs rational.
3

How to Write the Answer

Mains
Worked example — decoding the question

“Critically examine Köppen's classification of world climates.” (15)
Explain its basis & codes, then weigh its merits against its limitations.

Introduction · ~20%
Note the need to classify climates; Köppen is the most used.
Body · ~60%
Basis (temperature + rainfall + vegetation); groups A–E and letter codes (f/w/s/m) with examples. Merits: simple, data-based, maps well, vegetation link. Limitations: empirical (ignores causes/air masses), rigid boundaries, underplays wind/pressure. Contrast with Thornthwaite (water balance). Use the groups diagram.
Conclusion · ~20%
Despite limits, Köppen remains the most practical scheme.
10-mark: ~150 words · ~7 min
15-mark: ~250 words · ~12 min
Common mistakes
  • Calling Köppen genetic.
  • Wrong letter meanings.
  • No merits/limits balance.
Model opening line: “To tame the endless variety of the world's climates, geographers group them — and Köppen's letters remain the common language.”
4

Prelims Questions

Prelims

30 interactive MCQs — previous-year questions are included and tagged with their year. Select an answer for instant feedback and an explanation; your score is tracked and you can review wrong answers at the end.

Practice set
Question 1 of 30
0/0
Score
5

Mains Questions

Mains

15 mains questions — previous-year questions are included and tagged. Write a full answer, then click Evaluate My Answer for paragraph-level feedback. Reveal the model structure after you attempt.

15 marks · ~250 words · ~11 min
Explain K&ouml;ppen's classification of world climates and assess its merits and limitations.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

15 marks · ~250 words · ~11 min
Compare the K&ouml;ppen and Thornthwaite schemes of climate classification.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

10 marks · ~150 words · ~7 min
Discuss the basis of Thornthwaite's classification.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

10 marks · ~150 words · ~7 min
Apply K&ouml;ppen's classification to India.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

15 marks · ~250 words · ~11 min
'K&ouml;ppen's scheme is empirical, Thornthwaite's rational.' Discuss.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

10 marks · ~150 words · ~7 min
Explain the letter codes used in K&ouml;ppen's classification.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

10 marks · ~150 words · ~7 min
Describe Trewartha's modification of K&ouml;ppen.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

15 marks · ~250 words · ~11 min
Critically examine the empirical approach to climate classification.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

10 marks · ~150 words · ~7 min
Explain potential evapotranspiration and the moisture index.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

10 marks · ~150 words · ~7 min
Describe the major climatic regions of the world.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

15 marks · ~250 words · ~11 min
Why has K&ouml;ppen's classification remained the most popular?
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

10 marks · ~150 words · ~7 min
Distinguish between empirical and genetic climate classifications.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

10 marks · ~150 words · ~7 min
Discuss the limitations of K&ouml;ppen's scheme.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

15 marks · ~250 words · ~11 min
Examine the usefulness of climate classification for geography.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

10 marks · ~150 words · ~7 min
Describe the tropical climate group of K&ouml;ppen.
Evaluate My Answer
Model answer structure

Intro: define the key term and give a one-line context hook.
Body 1: conceptual / historical basis with a named fact, date or example.
Body 2: evidence and analysis — sites, inscriptions, coins, archaeologists.
Body 3: limitations or the counter-view (balanced).
Conclusion: a specific, reasoned judgment / way forward.

← Weather & Climate Hydrological Cycle →