How to Reduce Humidity in House: 11 Fixes That Work

Quick answer: To reduce humidity in your house, measure it first with a hygrometer, then aim for 30–50% relative humidity, the range the EPA recommends. Run bathroom and kitchen exhaust fans during and after use, vent your dryer outside, fix leaks and drainage, run your AC, and use a compressor dehumidifier in damp areas like basements.

If you’re wondering how to reduce humidity in house air without guessing, the good news is that most homes need only a few changes. Sticky air, foggy windows, a musty basement and mildew on bathroom caulk all point to the same problem: more moisture going into the air than leaving it.

This guide walks you through finding the source, fixing it room by room, and picking the right equipment when fixes alone aren’t enough.

What humidity level should your house be?

The EPA recommends keeping indoor relative humidity (RH) between 30% and 50%, and ideally below 60% at all times. Above that, mold, mildew and dust mites thrive. Basements should stay below about 50–60% year-round.

Indoor RH	What it means	What to do
Below 30%	Too dry: static, dry skin, cracking wood	Stop dehumidifying; consider a humidifier in winter
30–50%	Target range	Maintain; keep monitoring
50–60%	Borderline: dust mites and musty smells start	Improve ventilation, run AC or a dehumidifier
Above 60%	Mold and mildew risk	Find the source and dehumidify now

In cold climates, aim for the lower end of the range in winter (around 30–40%). Warm, humid indoor air hitting cold glass is what causes condensation on windows.

What causes high humidity in a house?

Moisture comes from two places: activities inside the house and water getting in from outside. A family of four can add several gallons of water vapor to indoor air every day just from normal living.

• Showers and baths without a working exhaust fan
• Cooking and boiling water, especially with the range hood off or recirculating instead of venting outside
• Clothes dryers that vent indoors or through a disconnected duct, and laundry dried on racks inside
• Basement and crawl space moisture: groundwater through concrete, poor grading, clogged gutters
• Leaks in plumbing, roofs or around windows
• Humid outdoor air in summer, especially in the Southeast and Gulf states
• An oversized AC that cools fast and shuts off before it removes much moisture
• Houseplants, aquariums and unvented gas heaters, which all add vapor

How to reduce humidity in house: step by step

1. Measure before you fix. Put an inexpensive digital hygrometer in the main living area, the bedroom and the basement. Check readings for a few days, morning and evening, so you know which rooms are the problem.
2. Use your bathroom exhaust fan every time. Run it during the shower and for about 20 minutes after. If the mirror stays fogged, the fan may be too weak, clogged with dust, or vented into the attic instead of outside.
3. Vent cooking moisture outside. Turn on the range hood before you start boiling, and put lids on pots. Recirculating hoods filter grease but don’t remove moisture.
4. Check your dryer vent. Make sure it vents outdoors, the duct is connected and the outside flap opens when the dryer runs. Clean lint from the duct; this is also a fire-safety step.
5. Stop water at the source. Clean gutters, extend downspouts at least 4–6 feet from the foundation, and grade soil so it slopes away from the house. Fix dripping pipes and seal window leaks.
6. Run your air conditioner. AC removes moisture as it cools. Set the fan to “Auto” rather than “On” so moisture on the coil drains away instead of blowing back into the house. Replace filters on schedule.
7. Use a dehumidifier where moisture concentrates. Basements, laundry rooms and damp lower floors often need one even when the rest of the house is fine. Set it to around 45–50% and use a drain hose so it runs continuously.
8. Ventilate when outdoor air is drier. On cool, dry days, open windows for cross-ventilation. On humid summer days, keep windows closed and let the AC and dehumidifier work.
9. Dry laundry and firewood outside the living space. Racks of wet clothes inside can raise room humidity noticeably.
10. Cut back on vapor sources. Group houseplants and avoid overwatering, cover aquariums, and never use an unvented gas or kerosene heater indoors.
11. Recheck after a week. If a room is still above 60%, look for a hidden source: a leak under a sink, a wet crawl space, or an oversized AC short-cycling.

How to lower humidity room by room

Basement

Basements are cool and surrounded by damp soil, so they’re usually the most humid space. A compressor dehumidifier with a drain hose is the standard fix. If you notice an earthy odor, start with our guide on how to get rid of a musty smell in the basement, and see our roundup of the best dehumidifier for basement use.

Bathroom

Run the fan, squeegee the shower walls and leave the door open after showering. A fan rated for your bathroom size (as a rule of thumb, about 1 CFM per square foot of floor for standard bathrooms) makes a big difference.

Kitchen

Use a ducted range hood and lids on pots. Run the dishwasher’s dry cycle with the door closed rather than cracking it open while it’s steaming.

Bedrooms

High bedroom humidity feeds dust mites in bedding. Keep the AC running on humid nights and consider a small compressor dehumidifier if readings stay above 55%.

Crawl space

A damp crawl space pushes moisture up into the floors above. Vapor barriers, sealing and a dedicated dehumidifier are covered in our guide on how to get rid of humidity in a crawl space.

Winter vs summer humidity

In summer, the problem is usually humid outdoor air getting inside. Keep windows shut on muggy days, run the AC and use a dehumidifier in the basement.

In winter, cold outdoor air holds little moisture, so the problem is almost always moisture created indoors. Exhaust fans and brief window airing help most. If you see condensation or frost on windows, lower indoor RH toward 30–35%.

The equipment that helps

You don’t need much. A hygrometer tells you if the fixes are working, and a compressor dehumidifier handles damp areas. For more options, see our full dehumidifier buying guide.

One honest note: small thermoelectric “mini” dehumidifiers remove very little water. They’re fine for a closet or small bathroom, but they won’t lower humidity in a living room or basement. Our guide to the best small dehumidifier explains which ones actually work.

How to keep humidity from coming back

• Keep a hygrometer in the basement and one main room, and glance at them weekly
• Clean the dehumidifier filter every few weeks and check the drain hose for kinks
• Clean gutters each spring and fall, and keep downspout extensions in place
• Clean bathroom fan grilles and check that the ducts vent outside
• Replace HVAC filters on schedule and have the AC serviced before summer
• Store firewood, wet gear and laundry outside living spaces
• Watch for early warning signs: foggy windows, musty odors, peeling paint, spots on caulk

If you already see mildew, clean it up while you bring humidity down. Our complete guide on how to get rid of mold and mildew covers safe cleanup.

If you clean mildew with bleach or other cleaners, wear gloves and eye protection, ventilate the room, keep kids and pets out, and follow the product label. Never mix bleach with ammonia, vinegar or other acids; it releases toxic gases.

When to call a professional

Call a pro if you see mold covering more than about 10 square feet (the EPA’s threshold for professional help), if moisture follows flooding or a sewage backup, if humidity stays above 60% despite a dehumidifier, or if water enters through the foundation. An HVAC contractor can check for an oversized AC or recommend a whole-house dehumidifier. If anyone in the home has breathing problems or allergy symptoms, talk to a doctor.

The opposite problem in winter? If your hygrometer drops below 30%, see our best humidifiers for bedrooms.

Frequently asked questions

What is the fastest way to reduce humidity in a room?

Close the windows if it’s humid outside, turn on the AC, and run a compressor dehumidifier with the door closed. A room usually drops noticeably within a few hours. Turn on exhaust fans if the moisture comes from a shower or cooking. Fans alone move air but don’t remove moisture.

Does running the AC reduce humidity?

Yes. An air conditioner removes moisture as it cools the air across its cold coil. It works best when set to “Auto” fan mode and sized correctly. An oversized unit cools too fast and shuts off before removing much moisture, which is why some homes feel cold and clammy.

Is 60% humidity too high in a house?

It’s at the upper limit. The EPA recommends 30–50% indoors and staying below 60%. At 60% and above, mold, mildew and dust mites grow more easily. If your readings sit around 60% for days, improve ventilation and run a dehumidifier, especially in the basement.

Do bowls of salt or rice reduce humidity?

Not enough to matter. Salt, rice and baking soda absorb a tiny amount of moisture, far less than what a single shower adds. For a closet or safe, a renewable silica gel dehumidifier works better. For rooms and basements, you need a compressor dehumidifier or better ventilation.

What size dehumidifier do I need for my house?

Most basements do well with a 35- to 50-pint unit under the current DOE rating, and large or very damp basements need more. Portable units treat one area, not the whole house. If several floors are humid, an HVAC contractor can assess a whole-house dehumidifier.

Can high humidity make my house smell?

Yes. Humidity above 60% encourages mold and mildew, which produce the musty smell many people notice in basements and closets. Lowering humidity stops new growth, but you’ll still need to clean existing mildew and wash or air out affected fabrics.

Ready to pick a machine? Start with our guide to the best dehumidifier for basement moisture, or read our Waykar 80-pint dehumidifier review.