What weather wise affects Freeview TV Signals?

[Dee_in_London]

I live in NW London and we get Freeview via Crystal Palace transmitter. Our TV Antenna is in the loft and has been like that for at least 5+ years with no issues. However very recently I'm getting picture breakup on certain channels such as Sony Channel (which used to be called True Entertainment I think)

Excluding things like rain, etc.
I think the picture is more reliable when it's colder outside?

 

[ericmark]

Isotropic prorogation the CB guys call it skip is where you have a cold and warm layer of air and the radio signal can go up hit that layer and travel for 100s of miles so you have radio contact far further than normal, but if it's below the transmitter aerial it reflects the signal away from the ground in the same way, so in Suffolk you can lose local transmitter and get Dutch transmitters instead. And the multiplex signals lower down the mast may work, but those further up the mast fail.

In the days of coal fires you could see the smoke go up then fan out as it hit the layer.