Why are TV signals weaker during bad weather? I know that the TV and radio waves that are received and transmitted are non mechanical waves.
However during storms or bad weather in general, the television signals get weaker and the program becomes laggy or terminates.
My electrician told me it is because due to the clouds the waves cannot reach the receiver properly.
Why exactly does it happen? Is it because there is high reflection and refraction occurring in the clouds?
But if so, why don't the signals get deflected frequently by the passing clouds?
 A: Most of the signals one receives for TV broadcasts are going to be in the so-called Ku band (12 to 18 GHz).


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*Around 10 GHz is the absorption peak due to orientation relaxation of molecules in liquid water (More about molecules and microwaves can be found here).


*Above 10 GHz, Lorenz-Mie scattering takes over. The effect is a noticeable degradation, commonly known as rain fade, during heavy rain (100 mm/h).
This Rain fade refers primarily to the absorption of a microwave radio frequency (RF) signal by atmospheric rain and losses which are especially prevalent at frequencies above 11 GHz. It also refers to the degradation of a signal caused by the electromagnetic interference of the leading edge of a storm front.
A: The electromagnetic waves that carry television, radio and WiFi signals are the same type of waves as the light waves that you eyes are sensitive to - they just have a longer wavelength. The water droplets in clouds, rain or fog disperse and absorb light waves, which is why you cannot see through clouds, and why you can see less far on a rainy or foggy day.
Clouds, rain or fog will also disperse and absorb television, radio and WiFi signals, although the affect is less than with light waves, because of the longer wavelength. However, if your signal strength is weak to begin with then clouds, rain or fog may further weaken it enough to cause bad reception. A single cloud may not have much effect, but a thick layer of cloud or a heavy rainstorm will have more effect on signal strength.
Also, lightning creates electromagnetic waves which may be picked up by your antenna or dish and interfere directly with your signal.
