if you can help it. Humidity is invisible, water vapor in the gaseous form; here’s what it looks like right now from space (Western U.S.): http://www.ssd.noaa.gov/goes/west/weus/wv-animated.gif

From Accuweather.com:
Accuweather Typical Summer monsoon graphic
From weather.com:

 Possible Effects of Indoor Humidity:
TOO DRY (<30%) TOO WET (>50%)
Damage to wood floors, furniture, musical instruments Termites, cockroaches, and other insects
Static electricity; electronic equipment damage Condensation and stains on walls, ceilings, windows
Increased dust Flaking paint and peeling wallpaper
Respiratory, throat, and skin irritations Mold, mildew, dust mite growth; allergic reactions