This was a big problem for Boeing when building their production facility for the 747 in the late 60's early 70's. They had such rain that they ended up paving the entire plant site before constructing onit!
In the US, helos are used to mix low level air on frosty evenings in apple country to gain a few more days of growing season or to prevent late frosts from damaging the delicate flowers in the spring.
The US Army used Skycranes to kill the fog at several bases in Vietnam by flying above the fog and hovering to mix higher level dry air into the fog.