We live in Northern Arizona and keep two humidifiers going in the house all the time. Go to Radio Shack and get a hygrometer to measure humidity. We try to keep it up around 30-40%. With two harps, several gutars and mandolins, and I'm not sure how many ukuleles we pay close attention to this. Outside humidity can often be in the single digits. We never have to worry about excessive humidity. One unexpected benefit has been the way it helps keep dust down. Sinuses, lungs and skin benefit, too. Good luck.