Running a Dehumidifier in Winter
Written by the Dehumidifier for Basement editorial team and reviewed for source accuracy. — last updated July 2026. Editorial policy · Report an error
Quick answer
Most compressor dehumidifiers should not run when the room temperature drops below 60-65°F unless they have a built-in frost sensor and automatic defrost cycle, since the evaporator coil can ice over and stop working. Check your basement temperature and your unit's low-temp rating before running it through winter.
Do basements still get humid in winter?
Sometimes, but less often than summer. Cold outdoor air holds far less moisture than warm air, so infiltration brings in less humidity. However, basements with a source of internal moisture — a leaky foundation, a laundry area, or a poorly insulated slab — can still sit above the EPA's 50% RH ceiling even in winter, especially right after snowmelt or heavy rain.
Why do dehumidifiers freeze up in cold basements?
A standard compressor dehumidifier cools air across a coil to condense moisture out of it. Below roughly 60-65°F ambient temperature, that coil can drop below freezing and ice over faster than the unit's defrost cycle (if it has one) can clear it. Once frost builds up, airflow drops and the unit stops removing meaningful moisture — see dehumidifier freezing up for troubleshooting steps.
| Basement temp | Standard compressor unit | Low-temp/frost-sensor unit |
|---|---|---|
| Above 65°F | Runs normally | Runs normally |
| 60-65°F | Marginal — watch for early frost on coils | Runs normally |
| 45-60°F | Not recommended — frequent icing likely | Designed for this range, check spec sheet for exact rating |
| Below 45°F | Not recommended for any compressor unit | Some rated to 41°F; check manufacturer spec |
Should I just turn it off for winter?
For many basements, yes — if RH naturally stays under 50% once the heating season starts and the space is cold, running a standard unit both risks frost damage and adds unnecessary cost per running cost. Check with a hygrometer first rather than assuming; some basements with active moisture sources need year-round dehumidification regardless of temperature.
Tools needed
- Hygrometer
- Thermometer (or check the dehumidifier's built-in temp display)
- 1Check basement temperatureMeasure ambient temp near where the unit sits — not just outdoor temperature.
- 2Check basement RHIf it's reading consistently under 50%, you likely don't need the unit running through the coldest months.
- 3Check your unit's low-temp specLook in the manual for a minimum operating temperature — commonly 41-65°F depending on model and frost-sensor presence.
- 4Decide: run, pause, or switch modesIf temp is below spec and RH is under 50%, unplug it for the season; if RH stays high despite cold, keep running only if the unit is rated for low-temp use.
- 5Inspect the coil before restarting in springCheck for dust buildup or leftover frost residue before plugging back in for the humid season.
What if my basement stays warm year-round?
Finished, heated basements that stay above 65°F through winter can keep running a standard compressor dehumidifier on auto-humidistat mode with no frost risk — see should a dehumidifier run constantly for guidance on leaving it on auto mode long-term.
How do I know if my dehumidifier already froze up?
Severity triage: is a dehumidifier the right fix?
Coils are clear, air blows normally, water collects as expected — safe to keep running.
Light frost visible on the coil but the unit still runs — turn off, let fully thaw and dry for a few hours, then only restart if room temp is above the unit's minimum rating.
Thick ice block on the coil, no airflow, or water pooling under the unit — turn off immediately and see dehumidifier freezing up before restarting.
🔴 Get free quotes from local waterproofing and mold professionals
Describe the problem and a local, licensed contractor can give you a free on-site estimate. No obligation. Quotes come from independent contractors; we do not perform waterproofing, inspection or remediation work ourselves.
Demonstration form — no lead provider is connected yet, so nothing is transmitted or stored when you submit.
Frequently asked questions
Can I run a dehumidifier in an unheated basement in winter?+
Only if it's specifically rated for low-temperature operation with a frost sensor; a standard compressor unit will likely ice over below 60-65°F.
Does cold weather damage a dehumidifier even if it's off?+
No, an unplugged unit sitting in a cold basement isn't damaged by cold alone. Just let it reach room temperature before restarting to avoid condensation on internal electronics.
Will a desiccant dehumidifier work better in winter?+
Yes, desiccant models don't use a cold coil and don't freeze, making them a better fit for cold basements and garages — see desiccant vs. compressor.
Does humidity really drop enough in winter to stop using it?+
In many climates yes, since cold outdoor air carries less moisture, but always confirm with a hygrometer rather than assuming — some basements stay damp year-round.
How long should I let a dehumidifier warm up after storing it in a cold garage?+
At least 2-3 hours at room temperature before plugging it in, to let any internal condensation evaporate and avoid electrical issues.
Keep reading
Sources and methodology
Guidance on this page is drawn from federal agencies and industry standards bodies rather than our own laboratory testing. We do not test appliances in a laboratory and we do not publish product measurements we did not obtain from the manufacturer or a government listing.
- U.S. Environmental Protection Agency — Mold Course & moisture control guidance (keep indoor relative humidity 30–50%)Used for: Target indoor relative humidity range and mold-growth conditions. Last verified 2026-07-29.
- U.S. Department of Energy — Energy Conservation Standards and Test Procedure for DehumidifiersUsed for: Why capacity ratings changed: the current federal test procedure and its rating conditions. Last verified 2026-07-29.
- ENERGY STAR (EPA) — ENERGY STAR Certified Dehumidifiers product finderUsed for: Certification status, Integrated Energy Factor (IEF) values, and sizing guidance for dehumidifiers. Last verified 2026-07-29.
- Association of Home Appliance Manufacturers (AHAM) — Dehumidifier certification program and sizing guidanceUsed for: Capacity-by-condition sizing ranges and certified capacity verification. Last verified 2026-07-29.
- U.S. Energy Information Administration — Electric Power Monthly — average retail price of electricity, residential sectorUsed for: Default electricity rate used in operating-cost estimates. Last verified 2026-07-29.
Written by the Dehumidifier for Basement editorial team and reviewed for source accuracy. Last updated July 2026. Found an error? Report it through our corrections policy.