Losing Sky In The Rain

[Prudie]

Does anyone else lose their Sky signal in the slightest rain or snow? We do all the time, I'm sure there's something wrong with the receiver?

[Hymie]

Then I would suspect the dish has somehow moved out of optimal alignment (knocked or fixings have become loose) – see others advice on maximising signal strength.
Another possibility is a poor connection between the dish and Skybox, possibly involving corrosion.

The attenuation due to the dish misalignment and/or poor connection is enough to push the system over the edge, with the extra signal attenuation caused by rain.