I don't think you can pick one locale and argue anything based on that. I've lived in the Midwest USA my whole life (over 50 years). The weather seems about the same as always. I remember 100 degree days when I was a kid in the 1970s. They are rare but they happen occasionally then as now (we haven't been above mid-90s here yet this year). July and August are hot and humid, as always. I can't say that I've noticed any trends up or down, but that doesn't mean that the data on global averages are wrong.

Are you seriously trying to cherry-pick a single outlier to refute a planet-wide data set?

FWIW: if your point was that you were expecting Mexico City to be hot like Cancun, you need to check a map. The city is in the middle of a mountain plateau at 7000' MSL!

Then you should know that Mexico City is similar to SF in that there are not extreme temperatures. Mexico City average high temperature monthly.. the low is 72 and the high is 81.

Mexico City is at 2200 meters. High altitude is going to be cooler.