Fahrenheit-literacy, at least in Australia, is practically zero for anyone under 60-70 that has lived outside the US.

Even folks who grew up with it. In Australia they have have spent the last 40 years using Celsius for everything. You tell them something in Fahrenheit and they're going to pause, have to think "How do I convert that".

But anyway, the point was that it's not false to say "The US is basically the only country in the world that uses the Fahrenheit scale."

Basically everywhere else DOES use Celsius.

For day to day understanding of weather and climate, using anything other than Celsius is going to confuse or frustrate more people than it's going to help. Regardless of whether they're in or out of the Commonwealth.