Temperature, Air Temperature
noun
The energy of the warmth will cause the temperature to go up and down. Energy goes up? Higher temperature because of more movement and activity. Energy goes down? Well, temperature gets colder and slower.
きおん
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
気温が急に下がった。
The temperature fell suddenly.
今日の最高気温は四十度です。
Today's highest temperature will be 40 degrees.
朝と夜の気温の差が激しいんです。
The temperature difference between the morning and night is intense.