An update on the previous post.I've realised that I can provide a lot more information by using folders in KML. I have made a file where every station is assigned to a folder according to the year in which data ceased, or 2011 if it is still current. The years are then grouped into folders of a decade or so.
The use of this is that in Google Earth, you can make the folders and subfolders invisible (hierarchically). On the left, near the top, there is a box called places. If you have brought up the station KML file, there will be a box called Temporary Places. If you open that you'll see the filename (crutem_end.sav), and below that you can expand to show the directory. Beside each entry is a little screen that you can click to toggle visibility.
So if you want to see which stations disappeared in the '80's, just blot out all other top folders. If you want to see what happened in 1988, go down to that level. If you want to see all current stations, blot out everything except 2011. And so on.
There is another file (crutem_start.kml) foldered according to start year, which you can treat similarly. It is an interesting historical exercise to click through as the US, say, gets populated with stations in the 1850's.
I'll put up similar GHCN files to replace the less efficient ones from last year.
I've replaced the contents of the crutem_all.zip file with these.