For custom cities in M2D you need the file from
here and just drop it into your windows folder with the weather cities file (I made my own that just covers Canada) and it has worked for me before. I'm guessing that for this build of M2D the file needs to be changed but that is far ahead of my capabilities. It's only a concern for me because I live almost 3 hours away from the nearest city and the weather is very different from there.