temper（制御する、調節する）、-ature（名詞の接尾辞）から。temper, body temperature, temperatureなどから派生した。
英語の語源
temperature
temperature: [16] Like its relatives temper and temperament, temperature originally meant ‘mixture’ (Philemon Holland in 1601 wrote of ‘a temperature of brass and iron together’). The modern sense ‘degree of heat’ emerged in the late 17th century, and seems to have evolved from another early and now obsolete sense, ‘mild weather’. This reflected the ‘restraint’ strand of meaning in the word’s ultimate source, Latin temperāre, which also survives in English temperance and temperate. => temper
temperature (n.)
mid-15c., "fact of being tempered, proper proportion;" 1530s, "character or nature of a substance," from Latin temperatura "a tempering, moderation," from temperatus, past participle of temperare "to be moderate; to mingle in due proportion" (see temper (v.)). Sense of "degree of heat or cold" first recorded 1670 (Boyle), from Latin temperatura, used in this sense by Galileo. Meaning "fever, high temperature" is attested from 1898.
例文
1. Serve the cake warm or at room temperature ，cut in squares.
などのケーキは室温まで温めたり冷めたりしたときに四角に切ってテーブルに運ぶ。
2.She was admitted to hospital with a soaring temperature .
彼女は高熱で病院に運ばれた。
3.If your child 's temperature rises,sponge her down gently with tepid water.
子供の体温が上昇したら、スポンジにぬるま湯をつけて体を軽く拭きます。
4.The temperature in the south will soar into the hundred.
南方の温度は100度以上に上昇します。
5.The star 's surface temperature is reckoned to be minus 75 degrees Celsius.