Humidity can't cause signal loss but moisture getting into poorly made connectors can. The only real solution is to redo the connectors, preferably with external compression fittings which have a rubber boot covering the connection.
Frank,
There is a reason sat dishes are mounted on steel posts and you have discovered it. It is sunlight that dries wooden beams unevenly that makes them bend. They will bend enough to put the dish out of alignment.
Verify that the steel mast is plumb. Inspect your signal level. Inspect the line of sight (LOS) for trees. Tighten all fittings.