Köppen climate classification

Key takeaways

Köppen climate classification belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Köppen climate classification to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Köppen climate classification from memory before moving on to harder problems.

Reference excerpt

The Köppen climate classification divides Earth's climates into five main climate groups, with each group being divided based on patterns of seasonal precipitation and temperature. The five main groups are A (tropical), B (arid), C (temperate), D (continental), and E (polar). Each group and subgroup is represented by a letter. All climates are assigned a main group (the first letter). All climates except for those in the E group are assigned a seasonal precipitation subgroup (the second letter). For example, Af indicates a tropical rainforest climate. The system assigns a temperature subgroup for all groups other than those in the A group, indicated by the third letter for climates in B, C, D, and the second letter for climates in E. Other examples include: Cfb indicating an oceanic climate with warm summers as indicated by the ending b, while Dwb indicates a semi-monsoonal continental climate, also with warm summers. Climates are classified based on specific criteria unique to each climate type. The Köppen climate classification is the most widely used climate classification scheme. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notably in 1918 and 1936. Later, German climatologist Rudolf Geiger (1894–1981) introduced some changes to the classification system in 1954 and 1961, which is thus sometimes called the Köppen–Geiger climate classification. As Köppen designed the system based on his experience as a botanist, his main climate groups represent a classification by vegetation type. In addition to identifying climates, the system can be used to analyze ecosystem conditions and identify the main types of vegetation within climates. Due to its association with the plant life of a given region, the system is useful in predicting future changes of plant life within that region. The Köppen climate classification system was modified further within the Trewartha climate classification system in 1966 (revised in 1980). The Trewartha system sought to create a more refined middle latitude climate zone, which was one of the criticisms of the Köppen system (the climate group C was too general).

Overview

The Köppen climate classification scheme divides climates into five main climate groups: A (tropical), B (arid), C (temperate), D (continental), and E (polar). The second letter indicates the seasonal precipitation type, while the third letter indicates the level of heat. Summers are defined as the six-month period that is warmer either from April to September or October to March, while winter is the six-month period that is cooler.

Group A: Tropical climates Tropical climates have an average temperature of 18 °C (64.4 °F) or higher every month of the year, with significant precipitation.

Af = Tropical rainforest climate; average precipitation of at least 60 mm (2.4 in) in every month. Am = Tropical monsoon climate; driest month (which nearly always occurs at or soon after the "winter" solstice for that side of the equator) with precipitation less than 60 mm (2.4 in), but at least 100 − ( t o t a l a n n u a l p r e c i p i t a t i o n ( m m ) 25 ) {\textstyle 100-\left({\frac {\mathrm {total\,annual\,precipitation\,(mm)} }{25}}\right)} . Aw or As = Tropical wet and dry or savanna climate; with the driest month having precipitation less than 60 mm (2.4 in) and less than 100 − ( t o t a l a n n u a l p r e c i p i t a t i o n ( m m ) 25 ) {\textstyle 100-\left({\frac {\mathrm {total\,annual\,precipitation\,(mm)} }{25}}\right)} .

Group B: Desert and semi-arid climates

Desert and semi-arid climates are defined by low precipitation in regions that do not fit the polar (EF or ET) criterion of having no month with an average temperature greater than 10 °C (50 °F).

The precipitation threshold in millimeters is determined by multiplying the average annual temperature in Celsius by 20, then adding: If the annual precipitation is less than 50% of this threshold, the classification is BW (arid: desert climate); if it is in the range of 50%–100% of the threshold, the classification is BS (semi-arid: steppe climate). A third letter can be included to indicate temperature. Here, h signifies low-latitude climates (average annual temperature above 18 °C (64.4 °F)) while k signifies middle-latitude climates (average annual temperature less than 18 °C). In addition, n is used to denote a climate characterized by frequent fog and H for high altitudes.

BWh = Hot desert climate BWk = Cold desert climate BSh = Hot semi-arid climate BSk = Cold semi-arid climate

Group C: Temperate climates

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Köppen climate classification

Start with the simplest possible case. Write down what Köppen climate classification claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Köppen climate classification before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Köppen climate classification ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Köppen climate classification

In research: Köppen climate classification appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Köppen climate classification in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Köppen climate classification is common in secondary-school and first-year university syllabi. It links to neighbouring topics Köppen climate types, so understanding it makes those chapters shorter.
In everyday life: Look for Köppen climate classification outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Köppen climate classification in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Köppen climate classification means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Köppen climate classification out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Köppen climate classification in simple terms?

The Köppen climate classification divides Earth's climates into five main climate groups, with each group being divided based on patterns of seasonal precipitation and temperature. The five main groups are A (tropical), B (arid), C (temperate), D (continental), and E (polar).

Why does Köppen climate classification matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Köppen climate classification?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Köppen climate classification.