Moisture Properties

• The average moisture property for a given location is an important climate factor. Dry air masses are continental and moist air masses are maritime. The term "humid" is sometimes substituted for maritime. Examine the average humidity condition for a location to determine its moisture type. For example Dallas, Texas, often has dry continental air in the winter after a cold frontal passage, while the year-round average air mass is maritime (humid). Moist climates exist in very cold places, such as Iceland, as well as in the torrid tropics.
  
  Antarctica is a huge desert, where the average annual precipitation is less than 7 in. per year of water equivalent. McMurdo Station, deep into the "ice cap" climate of central Antarctica, gets less than one inch of precipitation per year, and can be considered an extreme continental climate. Annual precipitation in most of Antarctica is less than the average annual rainfall observed in Phoenix, Arizona.
  
  

Temperature Properties

• Temperature patterns vary due to seasonal changes from summer to winter, and are also strongly impacted by elevation. A climate with long, very cold winters and short cool summers will be an arctic climate. Search the map for a location near the ocean at about 40 degree north latitude. Imagine how this climate might vary from one at the same latitude 500 miles inland. Look up the climate report from the National Weather Service for both locations and see if you answered correctly. Repeat the process for several other locations around the U.S. Temperature types include tropical, sub-tropical, mid-latitude and polar.
  
  

Putting It Together

• Combining the moisture and temperature properties allows you to begin classifying the climate type. A city on the American Gulf coast will be a Maritime Sub-Tropical climate, while Phoenix has a Continental Tropical climate. Choose several other locations around the world and estimate their climate types from temperature and moisture properties.
  
  

Elevation Also Important

• Identifying average moisture and temperature properties for a given location helps you zero in on its climate type. Another important factor to consider is elevation. The average temperature decreases about 4 degrees for every 1,000 feet, so Denver, Colorado, is much colder on average than Kansas City even though the two points are near the same latitude.