°H, A Human-Centric Temperature Scale

Here’s a somewhat silly idea that has been bouncing around in my head for a few years. It’s a new temperature scale. Not aware of anyone else having this idea, but it must have been thought of before, no? Perhaps with a different name.

Why would such a thing be needed? Well, a little backstory…


Growing up in California, we used and continue to use the Fahrenheit temperature scale, unfortunately keeping us out of sync with the rest of the world. On the surface, it is a bit nonsensical and occasionally a cause for others to poke fun at those “backwards Americans.” Let’s take a closer look:
  • 32°F, is the freezing point of water
  • 98.6°F, is body temperature
  • 212°F, the boiling point of water (at standard atmospheric pressure)
Weird, huh? Thirty-two degrees feels arbitrary and hard to remember. It doesn’t make much sense for the freezing point of water (nor its boiling point). On to the warmer temperatures.


One handy feature of Fahrenheit however is that it is great for describing the weather, a fact likely unappreciated by metric-only users. First, it has more “resolution” without resorting to decimals since the degrees are smaller. Second and more importantly, each ten degrees or so describes a useful block:
  • 50s and below - cold!
  • 60s - Cool, need a light jacket or sweater
  • 70s - Perfect for typical activities
  • 80s - Getting warm, shorts preferred
  • 90s - Summertime baby! Sandals. Too hot to be inside w/o AC.
  • >= 100 - Insufferable (without countermeasures)
  • 110-120 - Death imminent, or what I like to call “Vegas in August”
Keep in mind these may shift a bit depending on whether a person is very large or small, their current internal temperature (say they just ran up a flight of stairs, or sitting at a desk under AC), current humidity etc, but you get the idea. Nice “round” numbers for everyday activities.
Third, and perhaps most useful, 100°F and over describes an unbearably hot day. (Unless in a tank-top and flip-flops, in the shade with a cold-drink, etc.)

This makes for a convenient mental model, and is more “metric-like” than it has previously been given credit for. Stay with me, metric peeps!

Fahrenheit Recap

  • 32°F - Freezing point of water - ✗ Arbitrary
  • ~50-99°F - Intuitive on a daily basis - ✔ Useful
  • 98.6°F, is body temperature - ✗ Arbitrary
  • 100°F+ - Unbearably hot - ✔ Useful
  • 212°F - Boiling point of water (at standard pressure) - ✗ Arbitrary

Celsius, aka Centigrade

In contrast, Celsiusis much more logical:
  • 0°C, The freezing point of water
  • 10°C-40°C, Typical day
  • 37°C, Body temperature
  • 40°C+, Unbearably hot day
  • 50°C - Death imminent, aka “Vegas in August”
  • 100°C, The boiling point of water (at standard pressure)
Or, at least it seems that way. In general, I’m a big fan of metric and its simpler calculation abilities, but Celsius is my least-favorite part. Let’s take a closer look at why.

Freezing Point of Water

Despite what you just read, I have to admit 0°, for the freezing of water is pretty damn useful, impacting everything from the selection of proper footwear in the winter to setting the freezer in the kitchen. Wouldn’t want to lose that.


Meh. As a “gringo” that’s been lucky enough to travel somewhat extensively. Weather is why Celsius is less impressive, and it’s a pretty big use case. From my stint in New Zealand, I learned that:
  • 9°C is pretty darn cold (houses there have little insulation).
  • Comfortable weather was from ~17 to 25 degrees Celsius or so.
During my times in Brazil, I learned that:
  • From 30° to 40°C, the weather becomes increasingly unbearable, and 40 lead me to start humming an ol' Ozzy favorite.
Sure, with a few years of familiarity these figures become second nature, but it's hard to argue these numbers are intuitive in a numerical sense.  Also, every day temps get squeezed into an narrow band around 20°.

Boiling Water

100° for the boiling point of water is logical too, right? Well, let me ask you a question, when was the last time you cared about the exact boiling point of water? Don’t know about you—but—I’m struggling to think of a single time in my entire life.

I don’t boil water often, but when I do, I turn the heat up on the stove and walk away for ten minutes, and later determine the progress of the boiling process not by thermometer, but by eyeball—looking in the pan to see what size the little bubbles are. This gives the needed information, no need for a thermometer. The actual number of degrees is never a factor and so could be just about anything really.

Perhaps you work in a laboratory or Japanese noodle house, and the situation is different for you. Ok, but for the rest of us, the feature of 100 degrees for boiling water is less useful than has been billed by metric advocates.

(Note also that as the atmospheric pressure is a factor, it is likely to not even be 100 degrees exactly at your elevation, shrug.)

Celsius Recap

Interestingly, the pros and cons of Celsius are opposite of those of Fahrenheit:
  • 0°C, Freezing point of water - ✔ Useful
  • 10°C-40°C, Every day temps - ✗ Arbitrary
  • 37°C, Body temperature - ✗ Arbitrary
  • 100°C, Boiling point of water - ✗ Not particularly useful.


Perhaps when we colonize Pluto, Kelvin will be more useful ;-) Absolute zero is not a big factor day to day for most people on Earth. Moving on.


So, these temperature scales have been bouncing around in my head for years and something always seemed off about them. Neither of the two most widely used seems to be fully optimized for humans living on Earth. A bit odd, don't you think?  How can we solve that? Could we combine the best parts of Celsius and Fahrenheit somehow?

You may have noticed (like I did) that the round numbers of 100°F and 40°C are quite close, in that they both describe an unbearably hot day at approximately the same temp.  Great, next note that there is a factor of 2.5 (100/40) between the two quantities.

My next thought was that, if we keep Celsius for its useful anchor at 0 degrees and multiply the rest by 2.5 to stretch a hot day out to 100° like Fahrenheit, might we get the best of both scales? That is, 0° for freezing and 100° for unbearable?

Introducing °H!

That's it.  Suppose we could call it Degrees Human or Humano, to give it a Latin flair, haha. It’s basically  H = Celsius × 2.5, and has the following properties:
  • Granular enough to ignore decimals most of the time - ✔ Useful
  • 0°H - Freezing point of water - ✔ Useful
  • 10°H-99°H - Every day temps as percent - ✔ Useful
  • 92.5°H - Body temperature ~ Arbitrary (a wash)
  • 100°H+ - Unbearably hot day - ✔ Useful
  • 250°H - Boiling point of water ~ Arbitrary, though mostly irrelevant (but easy to remember at least)

In short, °H is optimized for humans living on Earth! What do you think?

(Thermometers above courtesy wikimedia.  This idea and post is donated to the public domain.  Looking forward to seeing it on the news one day, haha, as unlikely as that may be.)

1 comment:

  1. <3 it.

    Though no discussion of temperature scales would be complete without degrees Rankine. https://en.wikipedia.org/wiki/Rankine_scale