What is the term for the amount of pressure that air exerts on a surface, which rises with fair weather and falls with storms?

• A. Barometer
• B. Hygrometer
• C. Temperature
• D. Barometric Pressure/ Air Pressure

Answer: (D)

Air pressure is the force the air pushes on surfaces, and it changes with the weather: it tends to be higher during fair weather and lower when storms move in. The term for that amount of pressure is barometric pressure, also known as air pressure. A barometer is the instrument used to measure it. So the correct choice is the measure of the pressure itself—barometric pressure or air pressure. Hygrometer measures humidity, and temperature is a measure of heat, not pressure. The barometer is the tool, not the quantity.