I can only speak for my area, Phoenix. There are about a hundred "weather stations" on my app (Weather Underground, wunderground.com) so I can check temperatures all over the metro area, about 60 miles x 60 miles. The temperatures reported have a range of about 5 degrees over that area, e.g. 105-110, and are distributed as expected with most around the average, in this example 107. There are a few puzzling outliers which are much higher, e.g. one station at South Mountain which in this example might be 112. One of the cooler ones is always at Sky Harbor.
I think this factoid about the location of temperature sensors may be outdated, or if things are as they are here, reporting can be skewed a little by selection. But not much. I have thermometers, they are cheap, both spring type and electronic, and an IR laser "gun" type sensor for surface temperatures, and they all check out close to official reports. Try it yourself! This is as easy as research gets!
I can only speak for my area, Phoenix. There are about a hundred "weather stations" on my app (Weather Underground, wunderground.com) so I can check temperatures all over the metro area, about 60 miles x 60 miles. The temperatures reported have a range of about 5 degrees over that area, e.g. 105-110, and are distributed as expected with most around the average, in this example 107. There are a few puzzling outliers which are much higher, e.g. one station at South Mountain which in this example might be 112. One of the cooler ones is always at Sky Harbor.
I think this factoid about the location of temperature sensors may be outdated, or if things are as they are here, reporting can be skewed a little by selection. But not much. I have thermometers, they are cheap, both spring type and electronic, and an IR laser "gun" type sensor for surface temperatures, and they all check out close to official reports. Try it yourself! This is as easy as research gets!