Each statement represents the primary learning objective for the corresponding section heading within this chapter.  After you complete this chapter, you should be able to:

• Calculate five commonly used types of temperature data and interpret a map that depicts temperature data using isotherms (Section 3.1).
  
  

• Discuss the basic daily and annual cycles of air temperature (Section 3.2).
  
  

• Name the principal controls of temperature and use examples to describe their effects (Section 3.3).
  
  

• Interpret the patterns depicted on world temperature maps (Section 3.4).
  
  

• Explain how different types of thermometers work and why the placement of thermometers is an important factor in obtaining accurate readings. Distinguish among Fahrenheit, Celsius, and Kelvin temperature scales (Section 3.5).
  
  

• Summarize several applications of temperature data (Section 3.6).

Temperature is one of the basic elements of weather and climate. When someone asks what the weather is like outside, air temperature is often the first response. From everyday experience, we know that temperatures vary on different time scales: seasonally, daily, and even hourly. Moreover, we recognize that substantial temperature differences exist from one place to another. In Chapter 2 you learned how air is heated and examined the role of Earth–Sun relationships in causing temperature variations across seasons as well as across latitudes. In this chapter, you will examine several other factors that act as temperature controls. In addition, you will learn how temperature is measured and how temperature data can be useful. Applications of temperature data include evaluating energy consumption, measuring crop maturity, and expressing levels of human comfort.

For the Record: Air-Temperature Data

• Basic Calculations

• Isotherms

Cycles of Air Temperature

• Daily Temperature Cycle

• Annual Temperature Cycle

Why Temperatures Vary

• Latitude

• Elevation

• Land and Water

• Ocean Currents

• Geographic Position and Prevailing Wind Direction

• Albedo Variations

  • Cloud Cover

  • Influence of Snow and Ice

• Other Factors Influencing Temperatures

Global Distribution of Temperature

Temperature Measurement

• Thermometers

  • Mechanical Thermometers

  • Electrical Thermometers

• Instrument Shelters

• Temperature Scales

  • Fahrenheit Scale

  • Celsius Scale

  • Kelvin Scale

Applying Temperature Data

• Degree Days

  • Heating Degree Days

  • Cooling Degree Days

  • Growing Degree Days

• Indices of Human Discomfort

  • Heat Stress

  • Windchill