I live in a rural area where the official Weather Service station is located at the small local airport among sand, rocks and sage brush. It is always at least 7 degrees hotter out there than anywhere else around.
Years ago....I used to jog in Tucson...always near the central park near the base. There were three or four official weather service stations in Tucson...of which one of the “trailers” were at the edge of this park.
I stood there one day (110 degrees), and was plain worn out from walking. There was the trailer, and it’s assorted collection devices. Surrounding the trailer and within twenty feet...was a four-lane intersection with tons of asphalt. Around the trailer itself...someone had landscaped the area with at least six tons of gravel and rocks. Toss in the sidewalk and a nearby parking lot, and this was a magnet for heat. The trailer was probably recording temps at three degrees above what the real norm should have been. I’m guessing that the trailer had been there for at least twenty years. I doubt very seriously that any of the local weather guys who were responsible for it....really cared. It was faulty numbers that they were collecting, but obviously....it just didn’t matter.
I’d make a guess that at least thirty percent of the data that the Weather Service collects each year....is faulty data. No one is willing to stand up, admit it, and fix the situation.
Nothing wrong with that. The problem from is from urban heat islands and specifically from taking temperature measurements in areas that have become urbanized over the period of record. That creates an artificial uptick in temperature averages when there was no actual temperature increase.