lpetrich
Contributor
Several schemes have been proposed for 
Climate classification.
A fairly simple one is the Aridity index - a way of quantifying how desert an area is. It is
(precipitation) / (potential evapotranspiration (PET))
where precipitation is the amount of rain and snow and the like, and PET is how much water can potentially evaporate from the land and its vegetation. This index has these designated ranges:
0 - (hyperarid) - 0.05 - (arid) - 0.20 - (semiarid) - 0.50
A more detailed one is Holdridge life zones. It is usually displayed as a ternary diagram. Its diagram is an upward-pointing triangle with the bottom axis being humidity, the top left axis being PET (increasing downward, lines going right downward), and the top right axis being precipitation (also increasing downward, lines going left downward). Horizontal lines are temperature (increasing downward).
Still more detailed is the Köppen climate classification and a modification, the Trewartha climate classification.
The Köppen classification is described in detail in Present and future Köppen-Geiger climate classification maps at 1-km resolution | Scientific Data and Köppen-Geiger - gloh2o - the latter one contains a climate-map forecast for continued global warming.
That scheme goes:
Climate classification.A fairly simple one is the
Aridity index - a way of quantifying how desert an area is. It is(precipitation) / (potential evapotranspiration (PET))
where precipitation is the amount of rain and snow and the like, and PET is how much water can potentially evaporate from the land and its vegetation. This index has these designated ranges:
0 - (hyperarid) - 0.05 - (arid) - 0.20 - (semiarid) - 0.50
A more detailed one is
Holdridge life zones. It is usually displayed as a ternary diagram. Its diagram is an upward-pointing triangle with the bottom axis being humidity, the top left axis being PET (increasing downward, lines going right downward), and the top right axis being precipitation (also increasing downward, lines going left downward). Horizontal lines are temperature (increasing downward).Still more detailed is the
Köppen climate classification and a modification, the Trewartha climate classification.The Köppen classification is described in detail in Present and future Köppen-Geiger climate classification maps at 1-km resolution | Scientific Data and Köppen-Geiger - gloh2o - the latter one contains a climate-map forecast for continued global warming.
That scheme goes:
- A: Tropical
- f: rainforest
- m: monsoon
- w: savanna
- B: Dry
- W: desert
- S: steppe / semidesert
- h: hot
- k: cold
- C: Temperate
- s: dry summer
- w: dry winter
- f: no dry season
- a: hot summer
- b: warm summer
- c: cold summer
- D: Cold
- s: dry summer
- w: dry winter
- f: no dry season
- a: hot summer
- b: warm summer
- c: cold summer
- d: very cold summer
- E: Polar
- T: tundra
- F: frost (perpetual ice)
- W: Wüste (German: desert)
- k: kalt (German: cold)