Hello piper-pilot:
Atmosferic conditions interferes in radio comunications. If your talk about Low Frequencies you may experiment a slight increase on distance. But if you are talking about Ultra Hi Frequencies is the reverse. The clouds and the rain are harder to penetrate (resistence) and introduces more attenuation and dispersion, as you can confirm with (at least) your satelite reception.
So if you live near an airport and catching low altitude flight (under the clouds) the diference is not significant, even a slight increase may be noticed. But when talking about high flights the attenuation increases.
I am a man devoted, long time ago, to comunications... and i have lot of experience on this matter. And i think, looking to your email adress ;) that also are you.
Sorry for my English.
73
Iceman