| A | B |
|---|
| air pressure | the push of the air in all directions against its surroundings |
| anemometer | a tool used to measure the speed of the wind |
| barometer | a tool used to measure air pressure |
| cloud | a mass of tiny droplets of water that condensed from the air |
| condense | to change from a gas to a liquid |
| evaporate | to change from a liquid to a gas |
| fog | a cloud that touches the Earth's surface |
| high pressure area | an area of higher air pressure than that of the surrounding air |
| humidity | the amount of water vapor in the air |
| low pressure area | an area of lower air pressure than that of the surrounding air |
| precipitation | any form of water that falls from clouds to Earth's surface |
| rain gauge | a tool for measuring precipitation |
| relative humidity | the amount of water vapor present in the air at a given temperature compared to the maximum amount that air could hold at that temperature |
| water cycle | the movement of water into the air as water vapor and back to the Earth's surface as rain, snow, or hail |
| windsock | a device used to show wind direction, consisting of a cloth bag that is open at both ends and hung on a pole |
| wind vane | a device shaped like an arrow, used to show the direction of the wind |
