[lbebber]

There was no snow in São Paulo AFAIK; and snow in the south of Brazil, which did happen, happens more or less yearly.

(just a minor correction, not arguing against your general point)

[buckie]

I can't cite that example, I just have a friend whose parents are there tell me a story about how they were saying how pretty the snow flurries were and how he had to inform them about how ominous it was for there to be snow there. It's possible that they were referring to the frost that Sao Paolo got (which is still pretty crazy), and the videos of snow from further south.