"We'll second that as if the humidity where humans are living in drops below 30%, noses and throats dry and often get scratchy feeling and sore like a sore throat cold and our lips start cracking. Below 20% a nose will even crack inside and bleed and a very big reason we stay away for deserts and the southwest."
I believe, and am sorry to hear, that you and your wife suffer in drier climates but your numbers are simply not true. We have lived in the Tucson area for 8+ years. Our humidity is typically 12 to 20% and we suffer no ill affects whatsoever. Quite the contrary, at temps up to 100 degrees 12 to 20% humidity is very pleasant.
Neither of us has so much as a cold in more than 8 years, no dry or scratchy throats, no cracked lips and we came from a relatively humid climate, San Diego (yes boys and girls San Diego is often 70% or higher but then they have that big blue thing to west).
Now come springtime they measure the pollen count in Tucson much like lake effect snowfall in Buffalo and allergies can be a serious problem when the high Sonoran desert is in bloom. Fortunately it is so beautiful we don't mind. :C
