Temperate climate

Temperate climates occupy the middle latitudes of Earth.

These regions sit between the hot tropical zones and the freezing polar regions. Geographically, they span from approximately 23.5° to 66.5° north or south of the Equator. While tropical climates often have very little temperature variation, temperate zones experience distinct seasonal changes. These areas usually have wider temperature ranges throughout the year. Many different factors work together to shape these climates. These include latitudinal position, sea currents, and prevailing wind directions. The size of landmasses, known as continentality, also plays a major role. Finally, altitude, or how high a place is above sea level, influences local weather patterns.

Scientists use the Köppen climate classification to define these regions. Under this system, a climate is labeled "temperate" (C) if the mean temperature in the coldest month is above a certain threshold. This threshold accounts for the persistence of frost. Some versions of this system use 0°C as the minimum. A broader definition may include continental climates, which are classified as D. These continental climates have more extreme temperatures. In these areas, the mean temperature in the coldest month is usually below 0°C.

The temperate zone is divided into several distinct climate types. The subtropical zone is found closer to the equator, between 23.5° and 35° latitude. These areas are heavily influenced by the tropics. They usually experience warmer temperatures all year. This results in long, hot summers and short, mild winters. Freezing precipitation is uncommon in these subtropical regions.

Within this zone, we find humid subtropical climates. These have long, hot, and humid summers with frequent convective showers. Warm ocean currents often exist in these coastal areas. In places like southeast China, a monsoon subtropical climate occurs. These regions have very chilly, dry winters and extremely heavy summer rainfall. Some areas report more than 80% of annual rain in just five months.

Another subtropical type is the Mediterranean climate. These climates are found mostly on the western edges of continents. They have a unique pattern of dry summers and wet winters. This happens because arid deserts on their equatorward sides bring dry winds in summer. Meanwhile, oceanic climates on the poleward side bring winter rain. Major Mediterranean regions include the Mediterranean basin, coastal California, and central Chile.

We also find subtropical highland climates in mountainous areas. These areas feature mild temperatures year-round. They can have four seasons in the subtropics or no marked seasons in the tropics. Some highland climates, like the Cwb type, have a strong monsoon influence with dry winters.

The middle latitude zone sits between 35° and 66.5° latitude. Here, the climate feels an equal influence from both polar and tropical zones. One major type is the oceanic climate. These are created by the on-shore flow of cool air from high-latitude oceans. This results in mild summers and cool, but not freezing, winters. Precipitation is usually spread evenly throughout the year.

Examples include northwestern Europe and New Zealand. In contrast, humid continental climates are shaped by large landmasses. These climates experience much more severe seasonal changes. They often feature hot summers and very cold winters. These are found in parts of the eastern United States, China, and Japan.

The subpolar zone marks the edge of the temperate region near the poles. These areas still have four seasons, but they are heavily influenced by polar air. Subpolar oceanic climates are found in places like Iceland, Scotland, and the Aleutian Islands. These regions are less prone to extreme temperature swings than continental climates. However, snowfall is more common here. In these maritime locations, temperatures exceeding 20°C (68°F) in summer are considered exceptional.

We also see rare cold summer Mediterranean climates in high-elevation areas like the Andes.

Temperate zones are vital for human life and biodiversity. The vast majority of the world's population lives in these regions. This is especially true in the Northern Hemisphere due to its large landmasses. These areas also support massive amounts of life. For example, southern Africa has seen about 24,000 described taxa. Farming is also a major activity because of plentiful rain and warm summers. Most agriculture happens in spring and summer, so cold winters have a small effect. However, extreme summer or winter weather can greatly impact food production.

Finally, urbanization changes how these climates feel in cities. Most large cities are located in temperate zones. The climate in a city landscape can differ from rural areas. One reason is that buildings and asphalt have a higher absorption rate for heat. Another reason is the burning of fossil fuels from vehicles and buildings. These factors cause the average climate of cities to be warmer than the surrounding countryside.