Propagation and atmospherics...

[Externet]

Good day.
What is known about the effects of dry weather; temperature and sun position in relation to 'local' RF ?

I experience a few television channels reception becoming marginal on dry weather, also by sunrise and sunset, and sometimes on hot days. The weirdest is the effect of wind bursts to a solidly mounted antenna that does not shake at all and absence of trees that could variably interfere with RF signals path.

 

[BradtheRad]

Sometimes a certain tv channel range (example, 5.3 to 5.7) will not pick up on my tv. There is no obvious cause for it. Weather conditions are not a reliable predictor

Usually I get success after moving the antenna to various spots on the wall.

Same with my favorite FM 88.5 radio station. There's always some static, some days less, some days more. It changes as I move the wire antenna to different spots around the room. Putting it near the window is not necessarily optimum. Placement sometimes brings in the station at 88.3 stronger than the frequency I wish to hear.

I live 20 miles from the transmitting antennas. My apartment is at the inside corner of a building. Ground floor. Not the most favorable reception. It makes my reception inconsistent and dependent on good atmospheric conditions, though I'm not certain what those conditions need to be for good reception.

 

[vfone]

In UHF line-of-sight propagation, if first Fresnel zone is free of obstructions, the wave propagation should not be much affected by dry or humid air or by sun position.

https://upload.wikimedia.org/wikipedia/commons/f/fb/Fresnel_zone_disrupted.png