You are supposed to wait until there is a settled high pressure before adjusting but that hasn't happened in the last two months! I have set it to the Carlisle Airport figure given on the BBC Weather website. It seems to be staying about right. We were wondering whether modern double-glazed houses would affect the readings. I can't find anything on that but did find this site about where to put them. It is on an outside wall about head height and nowhere near a radiator so that should be right.
