“Weather Service’s own requirement of being 30 meters away from artificial heating or reflecting sources such as pavements or building.”
I would be shocked if even temperatures 30 meters from a brick building or asphalt parking lot; didn’t show at least 1 degree warmer than something measured much further away.
When I was doing some MetNav duties for the AF the temp and humidity “boxes” had very strict guidelines. Ever since they went digital those guidlines were scrapped. Big mistake.