NOTE: I am not sponsored by any of the products shown in this video, nor do I approve of any product advertised added to my videos by YouTube.

Humidity, or "Relative Humidity" (the water vapour in the air) and temperature (and temperature changes) affect us, AND our precious guitars.
This is how I monitor both and protect my instruments against possible damage.
Products mentioned : Music Nomad MN35 hygrometer, and Humitar. Thermpro TP55 and Kontrol silica bags (none sponsored)