Never. It's either no units (theoretical physics), eV (particle physics) or Kelvin/Celsius for experimental physics.

Technically there is Rankine if you want to do thermo in imperial units.

Technically, Rankine and Fahrenheit are not imperial units.

I've only known engineers to use Rankine and they hate it. I've never known a scientist to use it.

When they look at a weather report in the US. Otherwise no.

You forgot about oven temperatures as well.

It took at least two burned dishes before I realized the recipes I was following called for Fahrenheit, not Celsius

What kind of fusion reactor of an oven do you own that goes up to 425 degrees Celsius?

Slight tangent, but Frank Stronach of Magna International, started his business smelting parts in their modified kitchen oven.

pyrolytic perhaps?

Burned dishes or burned houses?

Touche.

My aussie friend who was a scientist said when he was in the us for about 15 years that he still used c for temp in lab but F for weather and it took him a while to realize that he had flipped and the 2 things had basically no relationship in his head.

Kind of a tangent, but I still firmly believe that for Earth weather conditions, Fahrenheit is a more intuitive scale. 0 is a really, really, really cold day and 100 is a really, really, really hot day. 50 degrees is neither especially warm nor especially chilly, 70 degrees is warm, 30 degrees is chilly, 20 and below are truly cold, 80 and above are truly hot, and if you go into negative numbers or above 100 degrees than you're in the "extremes".

Cold and warm are relative. 0 for freezing / snowing and 100 for boiling gives you a much more understandable range. Honestly, US metrics don’t make any kind of sense anymore...

Except for weather, it’s never 100 C outside, or else we’d all die.

Yeah but it's still a very useful point where 100 should be, e.g. when you go to a sauna you know more precisely what to expect.

While it's true that 100C doesn't have any weather meaning, 0F being "very cold" isn't particularly objective. I just looked it up, and apparently 0F is only about -18C. Whether -18C is "very, very cold" depends a lot on where you're from and what you're used to. I'm Canadian and I certainly wouldn't characterize -18C as "very, very cold". -30C maybe. 0C has a fairly objective interpretation in terms of weather: it's the point at which puddles start to freeze into ice slicks.

Canada is a very cold country ;)

Some. Not the physicists or astronomers, but some Americans who work with data from non-scientists regularly stay with the units in the data. Some engineers, those who are dealing with older equipment, stick with the units used when the equipment was built. US pilots and aerospace generally still talk in knots and feet of altitude.

Mountain climbers in the US typically also use feet for elevation. Compasses sold in the US also have different markings for measuring the Universal Transverse Mercator grid(1:24,000 and 1:50,000 in the US) and rulers(inches, feet). 1:24,000 is used on USGS 7.5-minute maps, and I believe 1:50,000 originates from an older map series, both of which have topographical lines marked in feet instead of meters. Altimeters sold in the US also customarily use feet although the digital ones can be switched to Meters.

I fly a '76 Cherokee pretty regularly and its ASI is in both knots and miles per hour, with MPH actually being the more prevalent unit.