My sensor is in a Stephenson Screen, but until I can find the other system, which is why I asked the question, I cannot tell.
I am used to there being a difference between the stations. I am in a thermal belt, according the the map, the other station is in a town area, somewhere. The heat island effect of buildings with tile roofs could easily account for the degree difference.
In winter it is the opposite. I am usually between three and five degrees warmer, with a katabatic air flow. The other station is in a cold sink.