Glossary of Weather-Related Terms

Watching weather is an interesting and practical hobby everyone can enjoy. For those new to the field, learn the lingo with this handy weather glossary.

Anemometer: An instrument that measures the speed (or force) and direction of the wind.

Barometer: An instrument that measures atmospheric pressure, or the weight of the air. The two types are the aneroid barometer (springs and bellows) and the mercurial barometer (mercury-filled tube).

Barometric Pressure: The atmospheric pressure as read on a barometer. Usually given in units mB (millibars).

Dew Point: The temperature at which air must be cooled at a constant pressure to become saturated. When the dew point and temperature get close, the result is fog.

Heat Index: Air temperature and humidity combine to give a reading of how the temperature feels. Hot climates feel hotter when humidity is high.

High Pressure System: An area with greater relative pressure. A barometer in this area would measure the atmosphere as being heavy.

Hygrometer: An instrument that measures moisture in the air. It's also known as a psychrometer.

Low Pressure System: An area with less relative pressure. A barometer in this area would measure the atmosphere as being light.

NOAA: The National Oceanic and Atmospheric Administration is a branch of the U.S. Department of Commerce. The parent organization of the National Weather Service, it promotes weather education and environmental awareness with an emphasis on atmospheric and marine resources.

Precipitation: Commonly known as rain, in weather parlance it is much broader. Precipitation is any form of water that falls from clouds. Rain, snow, drizzle, and hail are some common examples of precipitation.

Weather Station: A collection of instruments that measure weather occurrences. Data from these observations is used to predict how the weather will change.