I wouldn’t wish humidity problems on anyone’s home. On the dry side, low humidity can cause everything from nosebleeds to cracks in dried-out wood flooring. And high humidity can encourage mold, warp wood or damage paint. Depending on how delicate your houseplants are, both extremes could also threaten their health.

But the smart thermostat, that unsung hero of the modern home, has hidden potential to fix this problem. These thermostats not only help gauge humidity, but they can automatically take action to prevent issues or alert you so you can maintain just the right indoor air quality. Here’s how to get started.

Yes, the right thermostat really can sense humidity

Today’s smart thermostats, including the Google Nest, have humidity sensors.

Google

Quick, what’s the humidity in your house right now? Most households don’t know, certainly not by checking traditional thermostats and definitely not when they’re away from home. Smart thermostats are different.

Today’s smart thermostats, including some of our favorite models like the Ecobee Premium and Google Nest thermostats, have built-in humidity sensors that are always detecting moisture in the air of your home. With the app on your phone, including popular platforms like Google Home and Alexa, you can check on humidity levels at any time, no matter where you are, before problems begin emerging.

With a smart thermostat, you can check humidity and get alerts from anywhere.Tyler Lacoma/CNET

Some thermostats even allow you to set alerts when humidity levels reach certain thresholds, so your phone will tell you when you need to take action. Humidity isn’t always related to temperature, either. When I asked Dan Bereiter, senior product manager of Honeywell Home Solutions at Residio, about these features, he advised a combo approach. “If the temperature looks comfortable, but the home still feels stuffy, clammy, or dry, humidity may be part of the issue. Watching both temperature and humidity can help homeowners make more informed adjustments.”

What if your smart thermostat doesn’t have a humidity sensor? That’s easy to address.

You can hook up a humidity sensor to nearly any smart thermostat

Thermostat satellite sensors are one of the best inventions for home heating.

Tyler Lacoma/CNET

I’ve experimented with an array of sensors that can measure humidity, from all-purpose versions from SwitchBot to the Wyze room sensor, the capable Aqara sensor and even an affordable humidity sensor from Ikea.

All these sensors can provide humidity readings to your thermostat, or independently to their own apps, which can still supply alerts to your phone about certain humidity levels. Many can also work with broader smart home platforms that can combine multiple devices like Google Home, Apple Home and Alexa, which can make it even easier to connect to thermostats and other devices.

With a press of this Ikea button, you can see the nearby temperature and humidity.

Tyler Lacoma/CNET

In some ways these smaller devices are even more useful than built-in humidity sensors, because you can move them to whichever room has the worst humidity problems, or the most delicate plants, etc., to get more accurate readings.

Then humidity levels can automatically turn on appliances

Humidifiers are easy to find at major retailers and are sold at a variety of price points.

MistAire via Amazon

With a smart humidity sensor, it’s now easy to set up a routine to let your house automatically tackle humidity problems. One of the best ways to do this is with a smart humidifier or dehumidifier. These include features that can connect to smart home platforms, too, which means you can set up an easy rule: “If the humidity reaches a certain level, turn on the humidifier/dehumidifier.”

What indoor humidity levels are best? Bereiter told me: “The EPA recommends maintaining indoor relative humidity (RH) between 30% and 50% because balanced humidity can help improve comfort, support HVAC system efficiency, and help protect building materials from excess moisture.”

You can set up a rule like this in just a couple of minutes, usually under the “Automations” section. The hardest part is connected sensors and appliances to Wi-Fi and adding them to apps, but as long as you have a reliable Wi-Fi router nearby, this shouldn’t be a problem.

These automations works best for larger models that can quickly adjust humidity, but of course the biggest will need to be refilled with water, or need a way to empty the water they’ve collected from the air (some use window units with a hose going outside). There are also whole-house dehumidifiers with smart capabilities by companies like AprilAire and TCL, as well as ways to connect to whole-house units with thermostats like Ecobee’s.

Of course, these smart appliances can get pricey. If you want to save money or already have a humidity device, you can usually make it smart by connecting it to a smart plug. These smart plugs can turn humidifiers/dehumidifiers on or off based on schedules and rules you set up in apps. Smart plugs are only around $10 to $15, so it’s a very cheap way to add smart features to an appliance you already have.

If you do want to add a smart plug to your appliance, double-check it can function with basic on/off commands. Not all humidifiers, for example, turn on correctly when controlled by a smart plug. I suggest scanning reviews online to see if anyone has tried using the appliance or a model from the same brand with a smart plug to make sure it works before you buy.

Some thermostats can even tap directly into AC and heat pumps

Cooling and humidity settings are more advanced then ever and can connect to current home systems.Tyler Lacoma/CNET

Setting up rules to automatically turn on humidifiers or dehumidifiers is an excellent use of the smart home, and your plants, pets, family and lungs will benefit. But many smart thermostats can do even more.

Thermostat models also have the ability to connect to supported air conditioner systems and heat pumps (they don’t even have to be smart). These systems can act as natural dehumidifiers when they turn on, so it’s an easy way to lower humidity and heat in a home when they become problematic.

One of my favorite versions is Google Nest’s Cool to Dry, because it’s nearly effortless to turn on and can work with any AC or heat pump as long as you have the right wiring – follow the link to learn more about the details. Nest even takes it a step further with its new thermostat capability Humidity Helper, which taps into existing humidifiers/dehumidifiers to automatically set up rules for you.

Honeywell Home smart thermostats can also connect to AC and humidity features, particularly Resideo systems. AprilAire also offers a whole home setup that allows smart thermostats to control AC, air purifiers and more. Remember, if these setups get too complicated for you, you can always contact an HVAC professional to connect everything for you or find out what your home supports.

Even without automations set up, you can still take action

Do all these smart connections and automations feel like too much? Don’t want to spend any more money on appliances? You don’t have to use them to improve humidity levels. Take manual action and use your thermostat’s humidity readings to make decisions about when to open windows, turn on your AC, flip on a humidifier and so on. More information from your thermostat means better decisions for your home, no matter how you go about it.

Humidity changes can even help you save money

Humidity management could even lead to savings.Tyler Lacoma/CNET

Humidity has such a big influence on how we feel at home, dealing with it may mean running your heating or cooling system less and potentially saving money.

“High humidity can make a home feel warmer than it actually is, often leading homeowners to lower the thermostat and forcing the AC system to work harder,” Bereiter warned me.

A combination of smart thermostat suggestions and eco modes, plus taking care of humidity, may be able to make your home feel cooler while also saving on your energy bills. However, be careful. Constantly using your AC or humidifier to control humidity can have the opposite effect and cost more energy, so work on hitting the sweet spot for savings.

Final note: Humidity can change significantly between seasons in some climates. Certain setups may work best in winter if your cold season is especially dry, or you may only need a humidifier setup in sweltering summers. Either way, smart thermostats and sensors can help out.

Tyler Lacoma

Editor / Home Security and Smart Home

Tyler has worked on, lived with and tested all types of smart home and security technology for over a dozen years, explaining the latest features, privacy tricks, and top recommendations. With degrees in Business Management, Literature and Technical Writing, Tyler takes every opportunity to play with the latest AI technology, push smart devices to their limits and occasionally throw cameras off his roof, all to find the best devices to trust in your life. He always checks with the renters (and pets) in his life to see what smart products can work for everyone, in every living situation. Living in beautiful Bend, Oregon gives Tyler plenty of opportunities to test the latest tech in every kind of weather and temperature. But when not at work, he can be found hiking the trails, trying out a new food recipe for his loved ones, keeping up on his favorite reading, or gaming with good friends. See full bio