Yes, the RH is dependent on temperature...and pressure.

Basically, in a closed system like you are describing, with a set amount of water in the air, if the temperature drops, the RH will rise.

Do a search for Relative Humidity on wikipedia and you should find a decent explanation. However there are way to many environmental factors involved to give you a simple RH vs Temp chart, like air pressure and vapor pressure. Remember that in a sealed system, if the temperature changes and the volume doesn't, then the pressure will also change.

Why do you ask?

spiffy