weather condition of the atmosphere at a certain time and place climate the average of all weather conditions in a particular region over many years atmosphere the layers of air/gases that surround the Earth humidity the amount of water vapor, or moisture in the air air pressure the force that air puts on objects front In weather, the edge of where 2 air masses with different temperatures meet thermometer measures air temperature barometer measures air pressure rain gauge measures the amount of rain that has fallen over a specific period of time anemometer measures wind speed wind vane an instrument that determines the direction from which the wind is blowing