Wladimir Koppen (1846-1940, was a Russian-born German botanist and climatologist who developed a systematic method of classifying the climates of the world based on long-term patterns of the distribution of temperature and precipitation around 1900. He continued to develop this classification into to late 1930s, along with his student and colleague Rudolf Geiger. The American climatologist Glenn Trewartha updated the system in the 1960s, and it remains the most used climate classification system up to the present day.
You can see a world climate distribution map by clicking here.
This webpage takes you through the stages of classifying a location's climate according to this system. You will need average monthly temperature and precipitation data, as well as the annual average temperature and total precipitation figures. (Highland climates are not included).
Please note that whether a letter in the climate code is an UPPER-CASE or lower-case letter can change its meaning -- be careful to record all letters in their correct case.
To begin classifying a climate, click on the picture of Koppen above.