Dry climates are located in the subtropics. Subtropical areas are located at about 20° to 35° north and south latitude. These climates receive very low levels of rainfall. Thus, the defining trait of this climate is its arid nature. These climates are the B climates in the Koppen system.
Dry Climates
The dry climates are located in the subtropical zone. They are regions of low rainfall. The low rainfall is caused mostly by a belt of high air pressure in the subtropics. High air pressure areas have clear skies and little rainfall. Dry climates are also caused when moist air is blocked by high mountains. Two plant communities are found in dry climates. These are the desert and steppe vegetation.
Desert (BW) Climates
The desert climate is the BW climate in the Koppen climatic classification system.
Desert climates may range from hot to cold. The hot desert climate has temperatures above the freezing point of water. On the other hand, the cold desert climate experiences a few months with below freezing temperatures.
The dry subtropical high pressure zone is responsible for deserts in Africa and Australia. The effect of mountains blocking moist air is responsible for the cold desert climates of Central Asia and South America.
Due to low rainfall, some desert areas have no vegetation. In other areas, plants that have adapted to dry conditions may be found. Xerophytes are plants that can live in arid regions.
Steppe (BS) Climates
A steppe climate is the BS climate in the Koppen classification system.
The steppe climates have a wet and a dry season. The wet season allows vegetation to develop. However, the typical vegetation associated with the steppe climate is a grassland.
Steppe climates are located mid-latitude locations. They are a transition zone between dry deserts and more moist climates. In contrast to the tropical savanna, the steppes are a cooler climate grassland.
Summary
The dry climates are compared below.
Table of the Dry Climate Types
| Dry Climate Type | Temperature Conditions | Rainfall Conditions |
|---|---|---|
| Desert | Hot or cold | Low rainfall year round |
| Steppe | Cool | Wet and dry seasons |
Reflections
Vocabulary
- climate
- desert
- steppe
Notes
- The dry climates have low levels of precipitation (rainfall).
- The desert climate has low rainfall throughout the year.
- The steppe climate has wet and dry seasons and is able to support grassland vegetation.
Bibliography
- An Atmosphere Study Guide
- About the Atmosphere
- Dry Climate, Maps of the World.
