> Climatologist and weather historian Maximiliano Herrera went so far as to call it [35 C+ temperatures in winter] one of the most "extreme weather events the world has ever seen".

Assuming the quote is not taken out of context and Herrera did say it, I'm not sure the facts are on Herrera's side. The world likely saw more extreme "weather events," such as the one that happened at the end of the Pleistocene. That's when the half-mile-thick layer of ice sitting over the northeastern part of North America melted to expose the land beneath.