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I often make the argument about whether metric is "better" being split by "is it better on paper" vs "is it better in day to day life" - and most metric stuff breaks down in the latter, meaning, the non metric systems seem to be perfectly fine in day to day life, but almost always better on paper.

Like Celsius - sounds great on paper, not any better (and in some ways, worse) in day to day weather/temperature.

One of the few exceptions I find is metric paper sizes. It's such a beautiful way of designing the sizes that is not only perfect on paper (pun proudly intended), is also totally practical in real life.

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> "is it better in day to day life"

Speak to a carpenter or construction worker from any country with the metric system. Measure anything by simple powers of ten and simple decimal shifts makes life so much easier. Quick, what is half of a yard-length beam less 12 1/16"?

But realistically - most things are standardized. Nominal sizes. 2x4's, a sheet of plywood or drywall is 4x8 feet, etc.

(In fact, the metric equivalents of construction units are all based on feet/inches converted to a round mm because construction sizes are much older than metric)

So yes maybe you're messing with lengths, etc. 100% true. But unless you're doing fine carpentry, it doesn't matter.

The other thing is that it's a system that divides by 2 multiple times - it's not totally random. But metric only divides by 10 and 5 cleanly. You can't do a "quarter" of anything. Which is fine... but I'm saying that both systems have their advantages and disadvantages.

Assuming you mean (3 ft / 2) - 12 1/16 inches, it's about 6 inches, which is probably the accuracy you need. But it's exactly 5 15/16 inches, which is also easy to do in your head. Carpenters do it all the time, and even a doctor can.

My head did 36" divided by 2, so 18", minus 12 1/16", so 5 and 15/16". That is harder than working with quarters or fifths of meters, but easier than thirds or sixths of meters.

I don't know which is better. Considering how nothing stops you from doing decimal inches or fractional meters, but people rarely do that, both ways seem fine.

33.3 cm is easy to measure out, and 99.9 cm is exactly 1 mm short of 1 meter, well within tolerances for carpentry. Narrower than the mark left by your pencil.

But also like, we have calculators…

Not sure how Celsius is worse? Its unit is the same of Kelvin, just shifted by 273. 0C is freezing, 100C is boiling. Some people say Fahrenheit is more representative of how people feel, but that is very subjective and biased towards the West and Northern hemisphere.

Celsius in a lab (or in cooking) is perfectly fine.

But as a way to describe daily weather (and thermostats) it's woefully inadequate.

The sum total of "comfortable" temperatures in celsius has to be squeezed between maybe 17 to 24 - why? you never ever use anything above 40 except when talking about people that died from a heatwave.

It's based on the freezing and boiling point of water _at sea level_ which almost none of us ever encounter (whether it's sea level, or the boiling point of water).

Fahrenheit is a much more intuitive scale (again... to describe daily weather or human temperature) - 0 - 100 better models the temperatures we experience daily, and you can intuitively separate into 10s, the way you "feel"

For example...

100s - honey, please, let's move to a cooler place.

90s - uncomfortably hot

80s - hot in the sun, not too bad at night

70s - you'd probably want a light sweater at night

60s - light sweater all the time

50s - medium sweater

40s - sweater, maybe a coat

30s - coat

20s - sweater and coat

10s - why am i living in this region?

0s - honey, please, let's move to a warmer place.

The point is that there's enough resolution to describe the actual human experience with temperature.

For everything else, celsius is perfectly adequate, totally agree.

FYI, none of this has ever made any sense at all to somebody who didn’t grow up with Fahrenheit. Numbers don’t need to go roughly between 40 and 100, and then occasionally 212 and 450.

The difference between 20 C and 20.5 C is not generally noticeable. The difference between 20 and 25 really is.

You’ll just have to face the fact that you feel comfortable with a really weird system that nobody else can see the point of, but it’s what you’re comfortable with. That’s OK, you’re allowed.

It's common here to say something like "this week it's in the 70s." In places that use Celsius, "in the 20s" must be too broad, so do they instead say something like "high 20s"?

Here in a metric country (Australia) they use words like cold, cool, warm, hot.

Otherwise people turn to BOM (Bureau of Meteorology) hour by hour / day by day records and forecasts of temp. and rain with radar cloud coverage - these just use nearest whole Celsius numbers, eg: https://www.bom.gov.au/location/australia/western-australia/...

Almost everything you've conjectured about "how they do it in a metric country" has been wrong; builders don't use a third of a metre, for example, everything is typically in millimetres - 1200, 1600, etc (aka, 1.2 metres, 1.6 metres) along side usages of 1 mm and 5 mm for small tolerances, expansion gaps, etc.

They don't use a third of a meter because, like you said, you can just use some number of mm or cm that is divisible by 3. We don't use decimal inches because fractions are easy too.

Why would you assume that this particular turn of phrase would be common at all?

People usually just say the temperature they’ve heard in the weather report, without giving a range. If you say “over 20”, people don’t assume “close to 30”, because then you would have said that.

Because it's really common here. This week it's in the 90s, which is very hot. The temperature changes day to day, so how do you give the approximate temperature for the week?

You’d just say “over 30” for that kind of temperature, or “almost 40” if it’s at the higher end. I think you’re taking your own unfamiliarity and just assuming that we’re all struggling because you don’t know how to translate what you’re used to, but I promise you nobody who is used to it is finding it inconvenient or difficult to use.

They also accidentally got MPH right for cars. Fastest highway is like 85. 100 is the fastest a normal car can go and also a reasonable point to arrest the driver.

I regularly see people going over 110 MPH on European highways. And no, I don't consider it reasonable to arrest people just because they reached middle RPMs on the top gear of their cheap SUV.

Celsius has plenty of resolution for this; in fact I would say Fahrenheit has too much. You can feel the change of one degree Celsius, you can’t really with Fahrenheit. To illustrate this, not only is your scale in tens, but I often only hear people quote the Fahrenheit temperature in tens. In Celsius we almost always give the whole number, because it makes a difference.

You can make pretty much the same chart for Celsius and it makes as much sense.

40 - scorching hot

35 - super hot

30 - sunny summer day

25 - nice warm weather

20 - nice breezy weather

15 - a little chilly

10 - bring a coat

5 - getting cold

0 - drivers be careful

-5 - is cold

-10 - seriously cold

Etc.

Body temperature also has a nice cutoff point of 37.0C before you start to worry.

> The sum total of "comfortable" temperatures in celsius has to be squeezed between maybe 17 to 24

30° is perfectly comfortable for me.

> biased towards the West and Northern hemisphere

The widest range of temperatures found in any country is the USA. In the continental US alone the temperatures easily exceed -50°C and 50°C in both directions (much colder if you include Alaska). The USA also has the largest temperature change ever recorded in a 24 hour period, at 57°C.

Merits of specific measurement systems aside, the USA is arguably the most representative single country on Earth when it comes to temperature and "how people feel". It has among the hottest, coldest, and most extreme temperature ranges ever recorded.

Yep, highest outdoor temperature ever recorded was in the US. Even if you live in Death Valley, F makes more sense than C.

I really don't get this argument. Why does more extreme temperature mean that F makes more sense than C?

It doesn't mean that. F is better than C for weather no matter what kind of climate you live in.

A few comments up, someone was saying F only makes more sense than C because you live somewhere with specific temperature ranges. But the US has all sorts of ranges.

Got it. But why?

Celsius isn't granular enough (people can perceive 0.5˚C changes), and anything above 50˚C is rare or nonexistent. 0-100˚F pretty much lines up with the extremes.

Empirically, my wife can perceive a 0° change on a bad day. The same temperature can be too hot and too cold at the same time. That said, I have never encountered a situation where 1°F makes any difference. If somebody feels bad, it takes at least 2-3°F change to make them feel good again. Celsius is granular enough for that. All workplace safety and food safety regulations in Europe are expressed in whole, non-fractional degrees Celsius.

What's so special about the number 50? Why aren't you comparing to 40°C instead? 40°C is a more useful boundary than both 50°C and 100°F.

Thermostats normally use 0.5˚C increments because people can feel the difference. Then they disable the decimals when in F mode.

50˚C is the highest temperature that regularly occurs in the hottest place I can think of, Death Valley. The point is, half the 0-100 range never gets used even in extreme settings. But yeah, in most places, more than half is unused.

Thermostats are made with way more granurality than needed, like body scales with 100 gram/quarter pound precision or battery testers with millivolt sensitivity. Most people have single zone HVAC with one controlling thermometer, and it's literally impossible for the whole house to have uniform temperature. And yet, most people are fine around the whole house, not just where the controlling thermometer is.

I still don't get why are you so fixated on 50°C. Why not 125°F? You'd get even more unused range if you go 0-125.

The drift is consistent if your doors aren't randomly open/closed. If I set my upstairs thermostat to 73˚F, the master bedroom with a closed door is always 71˚F. Downstairs thermostat is 70˚F, office is also 71˚F. We don't care about ±1˚F when working but do care when sleeping.

Also, I get some measures being pointlessly precise just cause it lines up with the units, but they deliberately add a decimal place to the displays to support ˚C, even in countries where ˚C is default. The same display could support 0.5˚F increments, but they intentionally don't.

> I still don't get why are you so fixated on 50°C. Why not 125°F? You'd get even more unused range if you go 0-125.

The 0-125˚F range gets used though. Usually 0-100 though. It's perfect.

"Just shifted by 273"

To be clear, I don't have strong feelings. Obviously in a lot of science/engineering fields we use Celsius degrees a lot. But we also us Kelvin absolute scale a lot which would be ridiculous for day-to-day usage.

I am used to Fahrenheit but it is also a finer scale and a nice round number for boiling is largely irrelevant for the vast majority of purposes. Yes, knowing the freezing point of water can be important but memorizing one simple number probably isn't a huge stretch especially that the reality differs based on a number of factors. Arguably, knowing that 0 degrees F means fricking cold is sort of a higher latitudes bias but I'm not sure the degree to which Celsius simplifies.

The problem with "0F is fricking cold" is that so is 5F, and 10F, and even 15F to many people; and the difference between, say, -10F and +10F is pretty much none for practical purposes. Whereas knowing whether it was +1C or -1C during the night can have major impact on road safety.

With literally everything else about those two scales being a matter of preference and getting used to, this is the only objective difference with real world impact. Very tiny impact but still. Focusing on this one thing is the only way to answer the question of which is better with anything other than "whichever you're used to, it doesn't matter whatsoever". And if you focus on this one thing, then by the slightest of margins, Celsius is objectively better.

<Slightest of margins

As someone who lives in a northern US state, there are so many other factors that affect winter road safety that aren't a binary above/below freezing temperature at sea level. I'm not really going to argue against Celsius but F is a very workable scale that has some (minor) benefits at human scale.

As far as I can tell, literally every single benefit of Fahrenheits I've ever heard of boils down to being used to dealing with numbers around 100 but not around -30. I have yet to hear about any such benefit that isn't 100% attributable in its entirety to being taught °F before °C at school.

All those other reasons are exactly why I said the difference is minimal. But that minimal difference is not zero. If you add every single such difference that exists between °C and °F, of which there's literally just one, then Celsius very clearly comes ahead, although by an amount way too small to matter.

Black ice is always dangerous. No matter how many other dangerous road conditions you can come up with, black ice is still one of them. And black ice happens exactly when the temperature crosses 32°F boundary multiple times. It's far more important to know if it was 31°F than to know if it was 30°F.

> Its unit is the same of Kelvin, just shifted by 273

You mean shifted by 273.15 because Kelvin doesn't have tidy fixed points at the freezing and boiling point of water, unlike Celsius and Fahrenheit.

Celsius and Fahrenheit are both utilitarian systems. Kelvin is the scientific system. Arguments about the relative utility of C° and F° are subjective and neither is particularly optimal for science.

Celsius isn't granular enough. Many digital thermostats will even add decimal places if you switch to Celsius mode that aren't present in Fahrenheit.

Secondly, the highest temperature ever recorded outdoors was 56.7˚C. So no matter where you are, from that to 99 is wasted.

I have a kitchen thermometer for making caramel (can't remember exact number but ballpark is 200C). I occasionally use my oven at 250C. My wife fires her ceramics in a kiln at around 1000C. I don't feel like I'm "wasting" anything here.

> Celsius isn't granular enough.

This argument would be reasonable if we didn't have to cut inches into 16 or 32 parts to approach decent granularity. At least we use decimal for cutting Celsius up...

As you said, it's occasional. Temperature describes weather more often than anything else. And there's no advantage to Celsius for the ovens either.

Yup, because neither has significant advantage over the other. The only place where Celsius imo has a slight advantage comes from how often the phrase "below freezing" is used when talking about weather. That to me suggests that 0C/32F has some special significance, and thus makes Celsius a bit more elegant because it acknowledges that point. The granularity doesn't matter too much, as long as we agree to use decimals for ease of calculations, instead of using 1/32nds or some other barleycorns.

Only Americans feel this way about Celsius. The only downside is that Celsius requires 3 digit precision to really accurately characterize what temperature a room feels. I would be willing to bet humans are woefully inadequate at knowing the temperature of the room they are in anyways

I dunno I’m in a room and guessed that the temperature was 72°F and sure enough it’s 72° in here.

I put more details here: https://news.ycombinator.com/item?id=49635310

I do concede the overwhelming majority of people that argue that one is better than the other (both ways) are basically just arguing "the thing I grew up with is better" - because when you probe further, there isn't really any supporting argument, just "I understand this system better because I grew up with it" but it's equally vacuous coming from people who grew up with Celsius.

I came to the US when I was 12, so I grew up with Celsius but didn't pay attention to the weather as a young child. But still, I've lived in both systems.

As an American, I find Fahrenheit much better for ambient temperature and body temperature, but I hate seeing it for things like melting points of materials and the like. I'm always thrown off by statements like 800-degree pizza ovens, because once you get above 500°F it is out of the realm of everyday measurements, and I have trouble mentally separating the values for metals melting in °C and "gee whiz" temperatures in °F.

All scientific and engineering use should probably eschew the customary measurements, even in the news. For example, in aviation, they use °C now unless your airplane is very old. Unfortunately, in the US we still use inches of mercury for pressure, both knots and MPH but never km/h or m/s, etc.

If it makes you feel better, in Poland we still use millimeters of mercury.

Why do you think Celsius is worse in day to day life?

Because in Celsius, 0 lets you know the water outside will likely be frozen and 100 lets you know the water in your pot is likely boiling. This is utterly useless information.

It is nowhere near as useful day to day as knowing 0°F means a very specific saltwater brine mixture will likely be frozen, and 90°F is kind of as hot as your insides. Or 96. Or 98.6 as the third revision decided.

Also the 0 and 100 is at sea level.

If you actually measure a boiling pot (assuming you aren't at the beach), it will likely not be exactly 100 degrees, but less (or more, haven't had my coffee so I can't calculate).

So for most day to day stuff, it's equally arbitrary. And pretty much _nobody_ needs a thermometer to tell if something's boiling, you wait for a rolling boil. Or frozen, you wait until it looks like ice.

So again, great on paper, but in day to day use, not necessarily more useful than F.

I find F way more intuitive for weather. The larger scale helps. 100 is hot. 0 is quite cold. Boiling point is irrelevant. 32 freezing is the only thing that feels arbitrary.

Yeah and freezing point is whatever because that moves anyway and also doesn't say a lot about whether or not there will be snow

in celsius:

50 hurts to the touch, your chip has likely broken and given off its black smoke 30 is good for swimming in cold water >25 is worth worrying about sun stroke. make sure to drink a lot of water 24-26 is a nice summer day 18-22 is comfortable room temperature >15 is good enough shorts weather 0-10 needs at least a light jacket <0 you have to be attentive about frost bite, but not worried -5 either wants gloves or good pockets -15 wants a sweater and jacket < -15 you should probably plug in your car -10 - -25 is good downhill skiing weather -20 - -27 is right cold, full winter gear: toque, scarf, mittens, thick socks, the whole kit and kaboodle, but still chic -30 - -40: ski version of the full winter gear, including snow pants, double socks, and good boots. both your warmest sweater and ski jacket

----

its really just what you grew up with that will make sense.

like, wtf is 72 and 54 and mid 80s? i have no backing reference to put them into scale, even after living in the states for a decade. 500, 275, 425, 150 do make sense in F for me because thats what ovens list

>like, wtf is 72 and 54 and mid 80s

Exactly what their relation to 0 and 100 would imply. Middle, ~75 percentile, 80+ percentile.

I find that increments of 1C are too small to be useful in daily life but increments of 5C are quite big. As a result, you can't really round degrees Celsius to a multiple of 5 whereas full precision integer temperatures are too precise. So for example 15C and 17C feel like different temperatures, but each 1C step from 15C to 16C to 17C is not really useful.

In contrast, it's very reasonable to round temperature to increments of 5 degrees Fahrenheit. So for example 58F and 60F are basically the same temperature as far as my perception is concerned.

It's literally does not matter in day to day life. In the end you get to X degrees is cold, Y degrees is perfect and Z degrees is hot regardless of C or F.

I grew up using C and now I'm using F, if I move to a country that uses C, I will switch again. Its meaningless.

This is the correct take. The better system is the one that you have intuition in - just keep using that one if building up intuition in a different system is not worth the cost to you. At least when it comes to temperature. :)

What are you talking about? The same can be said about 59F (15°C) and 60F (15.56°C)

"One fahrenheit increment doesn't feel like anything"

At least Celsius are grounded in reality, should I be worried about ice? Just check if temperature is below 0°C. But hey you may need to check if your solution of water, ice and ammonium chloride is frozen, so I just need to check if below 0F. That's probably something you do often right?

theyre both grounded in reality because the represent real temperature conditions.

theyre both just arbitrary degrees though, since 0 isnt actually 0. they both have better alternatives too - Kelvin and Rankin. your criticism about freezing applies to celsius too. freezing is at a certain pressure and temperature, so both the 100 and 0 celsius only sometimes describe boiling and freezing

I can sense 0.5C changes when I set my AC at home.

1990s LCD HVAC thermostats that didn’t go down to half degrees had better precision when set to °F vs °C.

There's also this famous comparison chart meme: https://www.reddit.com/r/slatestarcodex/comments/t0lnjt/fahr...

...making the point that Fahrenheit's 0-100 range is better suited to normal day to day measurements than 0-100 Celsius. The numbers that feel easiest to communicate with are scaled nicely relative to the range of temperatures you most often want to communicate about.

i assume most of it is a joke?

> It is more precise. Fahrenheit has more frequent degrees, allowing for greater resolution with analog thermometers.

this is really about the graduation and size of the thermometer? you can print a useful line pitch as you like, and have it represent what you want, where thats a 0.25C, 3F, 10c or whathaveyou.

everyday temperatures are pretty well centered around 0C, half the year above, the other half below, and the 10, 20, 30, and 40 increments feel quite similar to each other in severity of the season. +30 is damn hot and -30 is damn cold. +/-10 is all mildly warm or cold, with +/-20 really being where you do seasonal acitivites like swimming or skiing.

as far as western units go, C fits fantastically for the the traditional western culture with 4 idealized seasons. I could see F being better for places outside the idealized west - eg. the american south/sun belt, the PNW, southeast asia, south america, a lot of africa, etc where the seasons are different

I like how the comments are like "um acxshaully as a Canadian [citation needed] [you forgot </s>](xkcd/234234)"

Yes we all know USA is the only country in the world.

Celsius is not really related to the metric system. It's just a temperature scale the entire world (minus the US) agreed to use.

The only connection off the top of my head is that mL of water increases by 1˚C if heated with 1 calorie. Which is annoying because 1 Calorie is 1000 calories.

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