The worst icing conditions are when the air temp is just below freezing and the air is very humid. This was the case most of the year on Mt. St. Helina in winter.

The icing was so bad some winters that the transmitter would be knocked off the air every few days by a build up of ice on the antenna.

I would have to drive to the site and knock the ice off the tower with a hammer. By the time I started back down, ice had already formed below me.