"Norman" wrote in message ...

In practice, I suspect that in most cases you would end up with the same
answer
using either method.

Hi, Norman,
Agreed, even MetO site thermometers are only accurate to +-0.2C so I can not
see the point of such worry about accuracy with means! Just throw to the odd
for goodness sake, I've been doing it for over 40 years. It ain't that
difficult!
As Graham said, it's all about the values around 0C.
Ken
Copley
Teesdale