This has always been my primary argument in favor of Fahrenheit. It makes sense for humans, which is all a majority of the population really cares about. In addition, it's more granular. Sometimes turning the thermostat up or down by 1C could be too much, where 1F is just right.

In science and math, I can see where having round numbers for commonly used temperatures would be useful, but if 0C and 100C are the only places that happens, it's not that hard to memorize 2 numbers.

You only think it makes sense for humans because it makes sense for you, where you live the same way you feel changing a thermostat by 1F is perfect but 1C is too much: that’s true for you, not universally.

Fahrenheit functionally requires you to be biased in order for it to seem like a good system.

It provides greater granularity in the range of human comfort, without descending into decimals. How is that not more useful for day-to-day human usage?

0F is cold, 100F is hot. I experience both of these temperatures outside where I live every year.

-20C to 40C seems much more arbitrary as a way to measure the zone humans mostly live in.

I would wager that the outdoor and room temperature are an overwhelming majority of human use for temperature. It seems like it would make sense to optimize for how temperature is more commonly used at a population level.

I would say those who see Celsius as a good system are also biased, because they grew up with it and it’s what they’re used to.

> 0F is cold, 100F is hot. I experience both of these temperatures outside where I live every year.

Most people never experience anywhere near 0F in their lives.

> -20C to -40C seems much more arbitrary as a way to measure the zone humans mostly live in.

The zone most humans live in does not routinely (if ever) get anywhere near -20, to say nothing of -40.

The -40C was a typo, should have been 40C, to mirror the 0F to 100F, rounding a bit to make it less silly. It’s been fixed now.

Millions do experience 0F, and it’s ok to not use the full range. At or around 0F is cold, as you move closer or beyond it, it’s cold. As you move closer to or beyond 100F, it’s hot. Most people would likely prefer to never deal with <0F or >100F.

Celcius is pretty intuitive actually. It takes atmospheric pressure into account, Water is pretty abundant on the surface of the planet, and life kinda depends on it. It's a remarkable substance and quite stable. I dont think theres another substance where we can see all three phases with kitchen appliances and still consume it. Equally good for bathing and drinking. I need steam to clean clothes and cook my food. Using water as a benchmark for how we measure temperature is remarkably useful.

With all of those examples, the actual temperature doesn’t really matter.

For drinking and bathing, people go by feel. In the kitchen, the freezer makes water freeze, and the stovetop will make it boil into steam, but exact temperatures aren’t really relevant here either. The same goes for ironing clothes, the iron just does it.

When I think about where explicit temperatures are needed in the home, the oven and thermostat are the two things that come to mind. Water is pretty irrelevant for both of those. For cooking or frying someone may monitor meat or oil temps, but those aren’t water. A hot tub might have an actual temp on it, but those tend to be around 100F, not 100C, as they are meant for humans, not boiling.

Water is an amazing liquid, but I still struggle to see how measuring all our temperatures based on it makes sense.

> When I think about where explicit temperatures are needed in the home, the oven and thermostat are the two things that come to mind.

But in that case in what way is for example baking a frozen pizza from the store at 400 to 425 degrees F more relatable/convenient/natural than 200 to 220 degrees C?

It's not. When it comes to an oven, F and C are equally arbitrary, so it really doesn't matter. Optimize for what people use most, and let the other random uses fall as they may.