Indirectly, and only within limits. A smart thermostat doesn’t remove moisture itself, but many can run the air conditioner in a way that wrings more humidity from the air, and some trigger a whole-home dehumidifier. On its own it cannot dry air below what cooling naturally achieves.
How does a smart thermostat pull humidity out of the air?
When the air conditioner runs, its cold coil condenses water vapor out of the air, which drains away. A thermostat with a "dry" or dehumidify mode extends cooling cycles slightly so the coil spends more time removing moisture, not just lowering temperature.
This is why managing indoor climate is really about heat and moisture together: the same cooling cycle that drops temperature also strips water from the air. Longer, gentler cycles remove more moisture than short blasts do.
Remote sensor humidity readings
Many ecobee and Nest systems pair a remote sensor in a bedroom or far room that reports both temperature and humidity back to the thermostat, so the dehumidify decision isn't based only on the reading at the wall unit.
What's an overcool limit and why does it matter?
To dehumidify, some thermostats will "overcool" a room by a set amount — often up to about 2–3°F below the target — to keep the compressor running longer. You cap that limit so the house never gets uncomfortably cold in pursuit of drier air.
Without a cap, humidity control could fight your comfort. The overcool limit is the compromise: enough extra runtime to matter, but not so much that indoor climate swings cold and clammy.
When do you need a separate dehumidifier for your heat pump or HVAC system?
When it's humid but not hot — spring, fall, or a damp basement — the AC or heat pump barely runs, so it can't dehumidify. A dedicated dehumidifier, portable or whole-home, handles moisture independently of temperature.
Heat pump vs furnace-and-AC HVAC systems
A heat pump system behaves a bit differently from a separate furnace-and-AC HVAC setup, since it uses the same coil for both heating and cooling. Some thermostats can switch a whole-home dehumidifier on directly regardless of which HVAC type is installed.
WiFi app control, scheduling, and energy report tracking for humidity
A WiFi-connected thermostat lets you set humidity targets through its app control alongside a temperature schedule, and many models fold humidity trends into the same energy report that tracks heating and cooling use.
Programmable vs learning humidity targets
A basic programmable thermostat holds a fixed humidity target you set once. A learning model can adjust its dehumidify aggressiveness based on your patterns, though the overcool limit still caps how far either approach will push.
C-wire, installation, compatibility, and zoning for humidity control
Dehumidify mode typically needs a C-wire for continuous power, and Honeywell and other brands sell adapter kits for older homes without one. Confirm compatibility with your HVAC system before installation, since not every system supports an extended dehumidify cycle.
Alexa, Google Home, and geofencing tie-ins
Voice control through Alexa or Google Home can check current humidity on demand, and geofencing can ease off dehumidify mode while the house is empty, resuming it as you approach home. With multiple thermostats, zoning lets one damp room dehumidify more aggressively than the rest of the house.
Energy savings from smarter dehumidify cycles
An ENERGY STAR certified Nest, ecobee, or Amazon-connected thermostat aims for energy savings by only overcooling when the humidity sensor actually calls for it, rather than running dehumidify mode on a fixed schedule regardless of conditions.
See the smart thermostats hub for models with humidity control, and the ideal indoor humidity level for target ranges. How we source these picks is in How We Rank.