Now I know that to measure earthquakes, geologists use seismic waves to determine

Geologists use seismic waves to learn about and establish the structure of the Earth’s interior.

If the water vapor content stays the same and the temperature drops, then the relative humidity increases. its vise versa.if the water vapor content stats the same and the temperature rises, the relative humidity decreases. so, yes, i'd say that temperature and humidity have a strong relationship.