Earth scales
Celsius
The degree Celsius (or simply °C) is a thermometric scale named after Earth astronomer Anders Celsius.
The Celsius temperature scale was designed so that the freezing point of water is 0°, and the boiling point is 100° at 1 Earth atm. In this scale, the temperature know as absolute zero is –273.15 °C.
The replicators aboard a Federation starship like the USS Enterprise-D are calibrated to the Celsius scale. (TNG: "The Defector")
Fahrenheit
The degree Fahrenheit (or simply °F) is a thermometric scale named after Earth physicist Gabriel Fahrenheit.
The Fahrenheit temperature scale was designed so that the freezing point of water is 32°, and the boiling point is 212° at 1 Earth atm. In this scale, the temperature know as absolute zero is –459.67 °F.
Sensors aboard 23rd century Federation starships can be calibrated to read in degrees Fahrenheit. However, like the mile, this antiquated means of measurement was used only on rare occasions. (Star Trek: The Original Series)
Kelvin
- You might also be looking for the alien species from the Andromeda Galaxy known as the Kelvans.
A Kelvin (or K) is a thermometric scale, named after Earth physicist and engineer Lord Kelvin. The scale was designed so that 0 K would be absolute zero, and the magnitude of each degree was equal to the Celsius scale. As a result, water freezes at 273.15 K and boils at 373.15 K
Other scales
Onkian
An Onkian is a temperature unit used within the Romulan Empire.
Twelve onkians are equivalent to a temperature on the cold side of the Celsius metric system. Admiral Alidar Jarok, after requesting political asylum on the USS Enterprise-D, ordered water with a temperature of twelve onkians from the replicator in his guest quarters (TNG: "The Defector")
Absolute zero
Absolute zero is the term used for the lowest temperature possible.
When the USS Enterprise first scanned the insectoid ship it encountered in 2270, it appeared to have a temperature of absolute zero, an impossibility. Later, it was discovered that the insectoid ship's energy accumulating wands, which collected many types of energy, were causing the sensors to return false data. The heat was being absorbed by the wands, leaving none to be detected. (TAS: "Beyond the Farthest Star")
- In "The Royale," Geordi La Forge stated that the planet Theta 116 VIII had a temperature of -291º Celsius, which is theoretically impossible. It should be noted that the measurement was referred to as "Fahrenheit" in the script.