Subtropics
Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from 23°26′09.7″ (or 23.43602°) to approximately 35° to 40° north and south.
Subtropical climates can also occur at high elevations within the tropics, such as in the southern end of the Mexican Plateau and in Da Lat of the Vietnamese Central Highlands.
Areas bordering cool oceans (typically on the southwest sides of continents) are prone to fog, aridity, and dry summers.
[2] According to the American Meteorological Society, the poleward fringe of the subtropics is at latitudes approximately 35° north and south, respectively.
[5] German climatologists Carl Troll and Karlheinz Paffen defined warm temperate zones as plain and hilly lands having an average temperature of the coldest month between 2 °C (35.6 °F) and 13 °C (55.4 °F) in the Northern Hemisphere and between 6 °C (42.8 °F) and 13 °C (55.4 °F) in the Southern Hemisphere, excluding oceanic and continental climates.
[8] According to the Wilhelm Lauer & Peter Frankenberg climate classification, the subtropical zone is divided into three parts: high-continental, continental, and maritime.
On the colder temperate side of the line, the total flora is adapted to survive periods of variable lengths of low temperatures, whether as seeds in the case of the annuals or as perennial plants that can withstand the cold.
[citation needed] However Wladimir Köppen has distinguished the hot or subtropical and tropical (semi-)arid climates (BWh or BSh) having an average annual temperature greater than or equal to 18 °C (64.4 °F) from the cold or temperate (semi-)arid climates (BWk or BSk) whose annual temperature average is lower.
Heating of the earth by the sun near the equator leads to large amounts of upward motion and convection winds along the monsoon trough or Intertropical Convergence Zone.
This regime is known as a semiarid/arid subtropical climate, which is generally in areas adjacent to powerful cold ocean currents.
Examples of this climate are the coastal areas of Southern Africa and the west coast of South America.
Areas that have this type of subtropical climate include Australia, Southeast Asia, and parts of South America.
[17][18][19] In areas bounded by warm ocean like the southeastern United States and East Asia, tropical cyclones can contribute significantly to local rainfall within the subtropics.
Some crops which have been traditionally farmed in tropical climates, such as mango, litchi, avocado and aloe vera, are also cultivated in the subtropics.
Parts of southwestern Australia around Perth have a Mediterranean climate as do areas around coastal South Africa.
[citation needed] According to Köppen, arid subtropical climates are characterized by an annual average temperature above 18 °C (64.4 °F), the absence of regular rainfall, and high humidity.
