[aksss]

I think Americans would relate to -90C even less. Many Americans are used to thinking about sub-zero temperatures, it seems less of a burden to conceptualize a really low temperature on the scale you're used to than to conceptualize a really low temperature on a completely different measuring system. The first question most Americans would ask is "What's the equiv of -90 in F?".

[sleavey]

Out of curiosity, what do Americans mean when they say "sub-zero"? 0°C or 0°F?

[aksss]

Sub-zero in the United States means below 0F. Ambient freezing temp isn't really a "cold" benchmark to people in northern climes, but sub zero (-18C) is a milestone that communicates a cold day from an experiential perspective. For instance, if I tell you a place gets below zero for a couple months, you know it's committed to being frozen, and that circumstantial variations like radiant heat from sunlight aren't going to get you back above 32/0F. Incidentally, freezers are set at 0F/-18C. So being in subzero temps is like being in a freezer, whereas being at 32F/0F could be a completely different experience based on radiant heat from sun, warm winds, etc.

[geenew]

Ambient freezing is certainly a benchmark in Canada. If nothing else it's important as a warning of possible black ice.

[bombcar]

"Below freezing" is when it goes below 32°F, "below zero" is when it goes below 0°F, and "ing cold eh" is when there's not a difference between C and F anymore.

[js2]

I've never lived anywhere in the U.S. that gets that cold, but in my experience, I don't think Americans say that much, but rather "below freezing" to mean below 0°C/32°F.

I happen to easily remember that 20°C = 68°F and usually use that when mapping the temperatures back and forth which works for the usual ranges where I've had to do so by just adding/subtracting 5/9 on each side.

I once translated literally on the run (running the Boston marathon) for a foreigner who asked about the temperature and got a Fahrenheit response.

When I've been in other countries that use C, I've always had to translate from C back to F in my head to make sense of the temperature. The longest I've ever been any place outside the US is 10 days, and that hasn't been enough time for me to get a feel of what temps are in C.

[aksss]

> I've never lived anywhere in the US that gets that cold, but in my experience [which we've established is none], I don't think Americans say that much.

It's a thing in Northern climes where the temperatures can get that cold. Everyone living in such places will know the term and you'll hear it frequently when talking about the weather or listening to weather forcasts.

[bigiain]

Where I come from, "It's fucking freezing!" colloquially means "under 10C". Because that's the lower edge of our "normal" climate here, so our houses are not insulated well for temps below that and central heating is rare because it's rarely needed. We also tend to not have a wardrobe with much that's suitable for temps down below 10C, unless you happen to have ski gear or winter motorcycling gear or whatever. (I've got one bike jacket which is too warm to wear at temps much above 10 or 15C - it gets very little use, in spite of me _really_ liking it...)

[bigiain]

I'm the opposite way. I understand the world in C.

I've got a few references in my head -40C = -40F (because magic), 0C = 32F (water freezing), 37C = just under 99F which I'm mostly approximate to 100F (body temp). 92C ~= 198F (espresso brewing temp), and 100C ~= 212F (boiling).

I use those to interpolate other F temps to whatever precision I need.

Brewing espresso I care about maybe half a degree C precision. Deciding what clothes to wear I only need to be within maybe 5 degrees C (so to me, 60F is "about 20% under halfway between 100F/37C and 32F/0C, so ~20% less than 18.5C - call it 15 = cold enough to take a jacket). For cooking I don't need to care to much about anything better +-20 degrees.

[JoeAltmaier]

0F of course. We get pretty cold here.

When some youtuber is camping out in 'sub-zero' temps, I smile. We call it 'warm' in Iowa when it gets above freezing in winter.

[js2]

I was hiking on the A.T. back in college mid-March and it was just a bit above freezing and rainy. My group (all from Florida) was bundled up inside a cabin to get out of the rain. In wandered some other college kids in shorts and tees, soaking wet. They were from Minnesota. I really don't know how they didn't have hypothermia, but I guess you can acclimate to quite a range of temperatures... for a while.

[selectodude]

The Hunting reaction is, at least in my experience living in a cold climate the better part of my life, a real thing.

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

[aksss]

And when it goes off the rails: https://en.m.wikipedia.org/wiki/Raynaud_syndrome

[JoeAltmaier]

Yeah at the top of Mt. Baldy we discovered a group of Georgian Scouts huddled shivering under their space blankets in a rock grotto. Meanwhile our Scouts (from Iowa) took off their coats and shirts and ran around like wild men. All about what you're used to!

[bigiain]

On the other hand, I, as a year round motorcycle rider, consider anywhere that regularly drops below 0C/32F top be "unfit for human habitation"... :-)

New York city is fun to visit, but I'd never live there...

[ceejayoz]

0°F. "Below freezing" would be below 0°C/32°F.

[hackeraccount]

Generally they mean a refrigerator brand but sometimes a character from the Mortal Kombat franchise.

[AnimalMuppet]

0°F.

[Sharlin]

Incidentally, –90°C/–130°F happens to be almost exactly the lowest natural temperature measured on Earth (–89.2°C, in Antarctica in 1982).

[wombatpm]

Protip: -40C == -40F