1 introductory paragraph Temperate climates on Earth have generally mild mean annual temperatures, with average monthly temperatures of more than 10 degrees Celsius in their hottest months and more than -3 degrees Celsius in their coldest months (Trewartha and Horn, 1980). The continent of Antarctica has a polar desert climate that is considered a moderate climate because it is not as severe as either a tropical or a sub-arctic climate.
The term "mild" has different meanings for different people. To some, it means having what they consider to be too high a temperature for too long at any one time. To others, it means having what they consider to be too low a temperature for too long at any one time. Still others see no problem with any amount of heat or cold over an extended period.
In general, mild climates are ones in which there is considerable variation in temperature throughout the year. This can be due to distance from a water source (e.g., ocean, lake, river), altitude, or proximity to a continental shelf (or other large landmass). For example, parts of Canada and the United States are far away from any body of water enough to significantly affect temperatures during most years. However, since these countries do experience occasional severe weather, including droughts and floods, temperatures during these events can reach levels harmful to humans and animals.
Temperate climatic zones are found between the equator and the North and South poles. The average temperature of the temperate zone's coldest months is lower than that of the tropical zones, while the average temperature of the temperate zone's hottest months is greater than that of the polar zone. Temperate climates are characterized by four seasons: winter, spring, summer, and autumn.
A sub-tropical climate is one that has some characteristics of both a temperate and a tropical climate. Temperatures usually range from 22 to 35 degrees Celsius throughout the year, with little variation. Rainfall is relatively constant, too. Sub-tropical climates can be found in regions near the tropics, but they can also occur several hundred miles away from true tropical heat and humidity. Examples include parts of Australia and New Zealand.
A Mediterranean climate is one that has warm temperatures and little precipitation throughout most of the year, except for occasional severe storms or hurricanes. This type of climate is found in areas around the Mediterranean Sea and in other coastal regions at high altitudes. It can also exist inland, provided there is enough moisture in the air that clouds form often enough to block out the sun during times of day when it is light outside. Areas with this type of climate experience only two seasons: hot and dry in summer, and cool and wet in winter.
Temperate climates are classified as having moderate rainfall spread out across the year or portion of the year with periodic drought, mild-to-warm summers and cool-to-cold winters (Simmons, 2015). Temperate climates can be found in many regions of the world including North America, Europe, Asia, and Australia.
In terms of temperature, mid-latitudes experience both warm and cold seasons, but not extreme temperatures. Boreal forests tend to have more seasonal variation in temperature than other forest types because trees lose water through their leaves during cold periods and must rely on underground reserves stored during warmer months. Forests that grow in warmer climates may retain most of their winter snowpack throughout the year.
The polar regions are defined as being at least 60 degrees north or south of the equator. Here, there is no true season because temperatures are always either very hot or very cold. Polar areas are known for their severe weather patterns including blizzards, ice storms, and tornados. They also have very short growing seasons due to low levels of sunlight exposure.
Mid-latitude climates are those that lie between the tropics and the poles. Because they are not as cold as the poles nor as hot as the tropics, mid-latitude climates have seasons that vary in length depending on where you find yourself within this region.