Well you have home and official sites that get factored into the error analysis now. BOS obviously has a much different geography than sites even a bit inland. ASOS temps are near instantaneous too so they catch warm ‘bubbles’ during the day a little better, but of course the 5 minute averaging smooths that out too. Some of these home sites are sheltered in shade and more and more have fans to negate solar effects. The sensor housing leads to a brief lag on Davis stations as well...other stations tend to have even more of a lag. What does it all mean? No clue...lol. But I think ASOS siting isn’t always perfect. Many have lots of dirt and runway nearby. Some have rocks around the sensor suite and they’re all mounted in concrete. So it’s not like they’re measuring over Kevin’s lush lawn or my continuously soggy backyard. But there are a few ASOS sites that do seem to be consistently warmer for whatever reason.