Weather question needed answered please!?

Question

I can't seem to figure this question out. If anyone could give me an answer, I'd really appreciate it! Thanks!

Explain why the RH (relative humidity) outside on a cold winter day could be quite high (very humid), but the RH inside is much lower.

Answer 1

Relative humidity is simply how much moisture a mass of air has compared to how much it can hold.  Colder air cannot hold as much water vapor as warmer air.  Therefore, for a given amount of water vapor contained in an airmass...the colder airmass will have a higher relative humidity.  Bring that air inside and heat it, and the relative humidity will decrease, unless more moisture is evaporated into it.

Answer 2

Indoor air is isolated from the sources of moisture that the

outside air has to maintain its RH.  The quantity of water in

the air remains somewhat stable but when the air is heated

and can then hold more water, the RH of the air drops

because its a measure of percent of saturation at a given

temperature.  When you raise the temp you're changing a

part of the equation that effects the measurement.

Answer 3

you have to have a source of moister to have a higher RH.. maybe its more humid inside..