On Fahrenheit, the Americans are surely right. For describing the weather, a system where the usual range is 30-100 is clearly more useful than one where it's 0-37, because you can say "high 70s" instead of the weirdly specific "about 27", and "low 40s" instead of the awkward "around 5 to 7".

I say this as a European who has never used Fahrenheit.