temperaturer

Temperature is a physical quantity that expresses the degree of hotness or coldness of an object or environment. It is related to the average kinetic energy of the particles in a system and is a fundamental parameter in thermodynamics, chemistry, and climate science.

Common units are Kelvin (K), Celsius (°C), and Fahrenheit (°F). The Kelvin scale is absolute, with 0 K representing absolute zero, the point at which molecular motion effectively ceases. The relation between scales is T(K) = T(°C) + 273.15 and T(°F) = (9/5)T(°C) + 32.

Temperature is measured with thermometers and sensors, using physical principles such as expansion of liquids, electrical resistance, or thermoelectric effects. Calibration relies on fixed points such as the ice-water mixture at 0 °C and the steam point at 100 °C (at one atmosphere) for the Celsius scale; precision instruments may reference primary standards like the triple point of water.

Temperature influences phase transitions, solubility, reaction rates, diffusion, and material properties such as density and electrical resistance. It affects weather and climate, engine efficiency, and human health.

Natural examples include the cosmic microwave background at about 2.7 K, air at room temperature around 20–25 °C, and the human body near 37 °C.

In English, the plural form is temperatures; "temperaturer" is not standard in English but exists as the plural in several languages such as Norwegian, Danish, and Swedish.