Signs Your Home Is Too Dry (and How to Fix It Without Overdoing It)

The signs

Common signs of dry indoor air and what the guidance says about each.

Sign	What it points to	Source
Hygrometer below 30%	Below EPA's recommended range	EPA
Dry, irritated nose and throat	Dry air can irritate and inflame the airways in the nose and throat	MedlinePlus
Gaps between wood floorboards in winter	Wood losing moisture; normal if they close in humid months	NWFA
Houseplants struggling	Most indoor plants benefit from more humidity than a heated home has	Penn State Extension
Frequent static shocks	Common in dry air	General observation
Dry skin and cracked lips	Common in dry winter air	General observation

Step 1: measure before you fix

Symptoms are a hint, not proof. A dry throat can come from a cold, mouth breathing or a heating vent blowing on the bed. Put a hygrometer, or an air quality monitor with a humidity sensor, in the room for a day, away from windows, vents and the bathroom. EPA's mold guide suggests using a meter to check humidity. If it reads 30 to 50%, the air is not the problem and a humidifier will not help.

Why homes get dry in winter

Cold outdoor air holds very little water. When it leaks in and is heated, its relative humidity falls sharply, which is why the problem peaks on the coldest days and in drafty homes. Forced-air heating does not remove water, but it circulates the dry air quickly. Sealing drafts around doors and windows reduces how much cold, dry air comes in.

Wood floors and furniture

The National Wood Flooring Association recommends keeping a home between 60 and 80°F and 30 to 50% humidity year-round, using humidification systems where needed. It says gaps that appear and disappear with the seasons are normal, but large gaps that do not close during more humid months are a reason to call a professional. Wood furniture and instruments respond the same way.

Houseplants

Iowa State Extension says many houseplants prefer 40 to 50% humidity and that misting does not work well, because the leaves dry quickly. Penn State Extension says most indoor plants benefit from more humidity than a winter-heated home usually has, with some cacti and succulents as exceptions. A room humidifier is the most effective fix. See humidifiers for houseplants.

How to fix it safely

1. Pick the right size. Match the maker's coverage figure to the room. CHOP warns that an oversized unit can cause condensation that fosters bacteria and mold.
2. Choose the type for your water. EPA says ultrasonic units are very efficient at dispersing tap-water minerals as white dust; evaporative units are not expected to. See ultrasonic vs evaporative.
3. Set it to 30 to 50%. EPA says not to humidify above 50%. MedlinePlus suggests about 40 to 50%.
4. Turn it down when windows fog. Condensation is EPA's sign of high humidity.
5. Clean it. EPA advises emptying and refilling portable units daily and cleaning them every third day.

Whole-house options

If every room is dry, one portable unit will not reach them all. A console such as the AIRCARE MA1201 is rated by AIRCARE for up to 3,600+ square feet in a tight house, placed near a cold air return. Homes with forced-air heat can also have a humidifier installed on the furnace by an HVAC contractor. Either way, keep the whole house within 30 to 50%.

When it is not the air

If humidity is in range and symptoms continue, look elsewhere. Dust from a dirty furnace filter, a heating vent aimed at the bed, or allergies can all cause a dry, scratchy throat. Anyone with persistent symptoms should see a doctor. For the full range of humidity guidance, see the ideal indoor humidity level, and for picks, the best humidifiers.