You learn new things in the strangest places.
Yesterday I was with a group of people, including a woman from Germany, chatting in a park and, inevitably, the conversation turned to the weather. We'd just had a couple of really hot days and were wondering just how high the temperatures had done. I'd heard 24C, while another had heard 21C. The woman from Germany then started wondering, if it was 21C "in the shade," how hot it must've been in the sun.
She was surprised when I explained to her that the weather stations are in the sun, not the shade, plus a bit about how they're supposed to be certain heights from the ground, distances from buildings, etc. I also mentioned that the readings we got were most likely from a weather station located at an airport outside our city. It turns out that in Germany, temperature readings are always in the shade! She assumed, of course, that it was the same all over the world, just as I assumed the same about our own temperature recordings.
So here was have yet another disconnect regarding raw data used to calculate global temperature averages. In the US and Canada, our weather stations record temperatures taken in open areas (sheltered from the elements, yes, but they are supposed to be away from trees and buildings). Never mind that an astounding amount of the raw data is corrupted. In Germany, they are deliberately taken from shaded areas. This is going to effect the raw data. What about other countries? What are their standards for official temperature recordings?
There was a time, not that long ago, when I trusted the numbers given out. Not anymore.