You guys use Celsius, not Fahrenheit?
Not ranting, genuine question, I thought UK is using mostly imperial units. Or is it that you are using a mixture of both metric and imperial?
Officially the UK uses metric units for most things, although the government-led drive to fully adopt metric units was abandoned a few decades ago (there used to be a quango called the Metrication Board). Membership of the EU further forced the adoption of metric units, although the UK still uses miles as the official unit for road distances - all the road signs are in miles. Interestingly, the roadside "mile markers" are in kilometres.
Official fuel consumption figures from the car manufacturers are always in litres per hundred kilometres, but everyone I know thinks and speaks in miles per gallon.
Some people - especially non-techy people - still measure lengths in feet and inches. Fahrenheit seems to have fallen largely out of favour nowadays. Older people still seem to think in ounces, pounds and stones, but not younger people.
Most of us buy milk by the pint, but the bottle is labeled in both systems. The one in my fridge says:
2.272l <---that is a lower case 'L'
4 pints
The construction industry is weird. You can ask for, and be sold, a length of "four by two" timber, but it will actually be sized in millimetres and will be thinner than 2 inches and narrower than four inches.
As far as I know, all our engineering and manufacturing industries are fully metric and have been for decades.
This mix sounds like a real mess, but by and large everything works OK. We got some concessions from the EU to keep miles and to allow pricing of foodstuffs in both metric and imperial, although the only people using the latter are the occasional market stall.
As a model engineer and clock and watch repairer, I find metric measurements to be very awkward. Many of the things I make require fractions of a millimetre, but usually microns are far too small. It happens that thousandths of an inch ('thou') are an almost perfect unit. Precision to a thou* is sufficient for most engineering purposes (virtually all amateur purposes), and in the world I work it is fairly rare to need dimensions bigger than an inch. So we have a unit - the "thou" - that gives integer values all the way from the limit of precision - '1' - up to the biggest size we will normally need - '999'. Even then it is easy to go bigger: one inch plus however many thou. That is why, when I bought my lathe, I bought one with imperial units, even though I live in a metric country.
*All affordable measuring devices, like digital calipers, will resolve measurements to 1 thou - some down to half a thou. But switch them to metric and they typically resolve to 0.02 millimetres, so almost all measurements are an awkward fractional number: 50 thou vs 1.27mm. It makes the mental arithmetic so much easier.