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Comment by username444 | Hacker News Reader

The argument that 0-100 being an intuitive and useful daily use scale is actually a good one.

However, everything else falls flat.

Nobody actually uses decimals with celcius, because nobody can tell the difference between 8.2 degrees and 8.7 degrees. It's just 8 and 9.

Zero being freezing is a critical number to know, because that's when you can get black ice (+/- wind-chill) and snow.

Knowing that 35 is grossly hot is no more difficult than knowing -32 is freezing.

Celcius has simple ranges: Below 0: it's freezing, bundle up 0-10: it's cold outside, wear a jacket 10-20: good for physical activity, sweater and light jacket required 20-30: it's comfortable outside 30+: stay in the shade

That said, all our appliances (oven, barbecue) use Fahrenheit and I have no idea what temperature to cook at in celcius.

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> That said, all our appliances (oven, barbecue) use Fahrenheit and I have no idea what temperature to cook at in celcius.

It surprised me when we recruited a developer from Canada, and on his second day at work he asked what temperature he should have set the oven to. I learned that Canada has appliances labelled in "American".

180°C is the most common oven temperature required, outside 160-200°C is unusual for normal cooking.

Ive always thought ovens could do fine with a five setting control.

Warming (180-200F)/90C

Low 300F/150C

Med 350F/180C

High 400F/200C

Broil

350 to 375 is pretty significant of a gap over several hours.

A High of 400/200 seems quite low. I'd definitely want a Very High of ~230-250 as well.

Canadian here, 325-450F is the typical range I've needed to use, pizzas are often what I cook at those hotter temps. That's about 160-230C.

There's a surprising inconsistency in Canada for units because of our proximity to the US. For body weight and height, nearly everyone uses lbs and feet/inches, but official records (on my driver's license for example) uses kg and cm. Like you said, most appliances are F. Distances are in km but property sizes are still often in sqft (because lots of products come from the US). The list goes on.

outside 160-200°C is unusual for normal cooking.

Huh? I probably do more than 50% of my cooking outside that range.

In an oven?

I gave the temperatures based on my experience of cooking "normal" things, like roast meat, roast vegetables, chips, bread and cake.

They happen to correspond to Wikipedia's idea of "Moderate" temperatures:

https://en.wikipedia.org/wiki/Oven_temperatures

Sure. Roast vegetables and bread for example I almost always do in the 200-250 range. Roast meat and fish I often do between 85-150, or 220-250 if I'm finishing them in the oven. Sometimes I'll start at 250 and then finish at 150.

It seems that in the extreme ranges of numbers (150+), the propensity for errors or confusion between the two scales gets riskier .

I was having an online discussion with someone in an electronics forum the other day, and we were talking about the ideal temperature for a soldering iron for a contact point using a particular type of solder and potentiometer.

He kept talking about setting the iron at 300 degrees. Now, my iron DOES have a setting up to 400 degrees, but in Celsius. He was talking in Farenheit, and had I not double checked with him, I would have fried my electronics to a crisp.

Do dial temperatures actually correlate to internal temperatures accurately at all? From what I've seen it differs wildly from oven to oven and you're better off just learning where the low, medium and high spots are.

225°C is the standard for most frozen pizzas, fries, pretty much anything, really.

My temperatures are for a fan-assisted oven, you can add 20°C for a 'normal' oven.

Although, I've never owned an oven without a fan-assist.

(And for what it's worth, Tesco's frozen pizza and chips should be cooked at 180°C and 200°C respectively, or 200°C and 220°C without a fan oven.)

Some pastries go even higher than this, like 250° C

> Zero being freezing is a critical number to know, because that's when you can get black ice (+/- wind-chill) and snow.

For those of us who don't live somewhere that ever gets black ice, this is not a critical reason.

Also, I suspect that wind-chill does not work how you think it works.

> That said, all our appliances (oven, barbecue) use Fahrenheit and I have no idea what temperature to cook at in celcius.

Spare a thought for those of us in enlightened civilisations that have to deal with myriad north-american based cookbooks ... but having said that, it'd take you a couple of weeks, with maybe a post-it note in the kitchen for the duration, to get the hang of the conversion rate.

That's OK, cooking in the US is weird - they use cups in their recipes that are a different size from those used in the rest of the world - because of course they use fluid ounces/gallons/etc that are a different size from Imperial cups/flu ozs/gallons, much less different from a standard 250g metric cup

To provide a counterexample to your statement "nobody actually uses decimals with celsius", when I switch the climate control system in my German-made car to Celsius mode it does use decimals: either .0 or .5, and the toggle moves the temperature up or down by half a degree.

Whereas in Fahrenheit mode the toggle moves the temperature up or down by a single degree, which seems cleaner and simpler to me (not to mention the F display uses 2 digits, while the C display uses 3).

> the F display uses 2 digits, while the C display uses 3

The °F display must use three digits as well when it's more than 37°C, which isn't that rare (at least for me, maybe not where you live).

I don't think the climate control system in any car can be set to pump out 100F+ heat. Usually it ranges from 60-80F.

Oh right, I thought it was for the external temperature sensor.

Yeah, climate control won't go that far of course. It also does use half degrees (only between 19°C and 23°C in my car).

The decimal point wasn't brought up against celsius specifically.

I think the biggest factor of c/f preference is just what you grew up with and are most accustomed to using every day.

There are objective landmarks outside of culture. The absolute zero, water freezing, water boiling, human normal body temperature, etc. It's better to use a unit where important ones are aligned to small practical. Probably something better than celcius could be designed.

Completely agree.

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