I like the graphic; it's very scary. But why were they not inclined to put actual units in the x-axis. Kind of hard to compare what is "cold" vs "normal" vs "hot" without having some kind of basepoint reference.
"Frequency of occurrence (vertical axis) of local seasonal mean temperature anomalies in unit of local standard deviation of Northern Hemisphere land areas."
It takes some time to unwrap the words there. The "anomaly" is the difference of an observation at a particular place and time from a seasonal and/or regional mean value. As you probably know, anomalies are pervasively used in geosciences. So in essence he's standardizing into what in statistics would be called a z-score,
z = (x - mu) / sigma
I guess the above is probably the reason the NYT graphic did not explain it fully.
I'm no climate science denier but stuff like this just adds fuel to the fire. You might say we're just supposed to take it on faith ;)