About The Temperature Scale
Created by Nolan Schleiff
Scroll down to go from the hottest temperature physics can describe to the coldest anything has ever been, about 43 powers of ten. The big number in the top left is the temperature you're looking at, in kelvin. Each stop is shown with how many times hotter it is than the next one.
Kelvin uses the same size degree as Celsius but starts at absolute zero, the point where nothing can get any colder. 0 °C is 273.15 K. Celsius and Fahrenheit are given wherever they help.
What's Simplified
- Temperatures are real but often approximate, and many stops, like lava, lightning and the Sun's corona, cover a range.
- Every stop is drawn at the same size on screen. The numbers tell you how different they are.
- The early-universe temperatures come from cosmology, not direct measurement.
- The coldest lab records describe how slowly a cloud of atoms is moving, an "effective" temperature, since a handful of atoms doesn't have a temperature in the everyday sense.
- A powers-of-ten scale never reaches zero, which suits the subject: absolute zero can be approached but never reached.
- Animations are illustrations, not simulations.
Sources
- Planck temperature and the definition of the kelvin: CODATA and the International Bureau of Weights and Measures (BIPM).
- Early-universe temperatures: standard Big Bang cosmology and the Particle Data Group review.
- Quark-gluon plasma: the ALICE experiment at CERN (2012).
- Fusion plasma: the ITER Organization.
- The Sun, Venus and Pluto: NASA fact sheets and the New Horizons mission.
- Lightning: the US National Weather Service.
- Vostok Station record: the World Meteorological Organization.
- Cosmic microwave background: COBE/FIRAS measurements (Fixsen, 2009).
- Boomerang Nebula: Sahai and Nyman (1997) and ALMA observations.
- Bose-Einstein condensate: Anderson et al., Science (1995).
- Coldest lab temperature: Deppner et al., Physical Review Letters (2021).
Get Involved
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A text version of every stop is available for screen readers.
See the other scales on the home page.
Scale Of Everything™ · © 2026 Nolan Schleiff. All rights reserved.