Updated on 5/26/26: This guide covers what temperature to leave a vacant house in winter and summer, what temp to set your thermostat when away - whether for a workday, a vacation, or an extended absence - and the practical steps that protect your home while the HVAC runs unattended. It's written for homeowners and seasonal property owners who want specific numbers, not vague ranges. Air Filters Delivered ships factory-direct air filters so your system has a clean filter before you hit the road.
In This Guide
- Short-Term vs. Long-Term Vacancy: The Rules Are Different
- What Temperature to Leave a Vacant House in Winter
- What Temperature to Set Air Conditioner When Away in Summer
- What Temperature Should I Leave My AC On While at Work?
- What Temperature to Leave House When on Vacation
- Can I Leave My House Empty for 2 Months?
- What Temperature Is Too Cold for a Vacant House?
- Does Climate Affect the Ideal Temperature for a Vacant House?
- Should the Thermostat Stay Constant in a Vacant House?
- Additional Steps to Take When Leaving a House Vacant
- Are Smart Thermostats Worth It for a Vacant Home?
- Should You Notify Someone About the House While It's Vacant?
- Frequently Asked Questions
Leaving a house empty sounds simple... until something goes wrong. A burst pipe in January. A mold bloom behind the drywall in August. Both are preventable, and both happen to people who thought they'd set the thermostat correctly before they left. The right setting depends on the time of year, your climate, and how long the house will be empty - and those three variables don't always point in the same direction.
Short-Term vs. Long-Term Vacancy: The Rules Are Different
A one-week vacation and a six-month snowbird absence call for genuinely different strategies, and most guides treat them the same.
For a short absence - a week or two - leave the system running. Cutting the HVAC entirely doesn't actually save energy when you're gone for a short stretch.
When you return, the system has to work much harder to bring the entire structure back to a livable temperature - not just the air, but the walls, floors, and ceilings, which have all absorbed the ambient temperature over days.
That recovery run costs more than the energy you saved while you were away. The Department of Energy has documented this effect, and it's why the 'just turn it off' instinct is wrong for anything shorter than a few weeks.
For a long absence - months - the math changes. If you drain the pipes and have no temperature-sensitive belongings, you can set the thermostat lower in winter or turn off cooling in summer. But honestly, most homeowners aren't in that situation.
Most people have plants, electronics, artwork, or furniture that doesn't tolerate extremes well, and the cost of running the system at a reduced setting for a few months is almost always less than the cost of replacing what gets damaged.
What Temperature to Leave a Vacant House in Winter
The recommended temperature to leave a vacant house in winter is 55°F minimum. That number has a specific reason behind it. Pipes in exterior walls and uninsulated spaces can freeze well before the interior air temperature hits 32°F.
The wall cavity temperature and the room temperature are not the same thing, and the gap between them is where burst pipes happen. So 55°F isn't arbitrary. It's the point at which most homes in most climates can maintain safe pipe temperatures even when outdoor temps drop hard overnight.
If your house has older plumbing, poor insulation, or sits in a climate that sees sustained below-freezing temperatures, bump that to 58°F. The extra few degrees of heat costs almost nothing compared to a burst pipe - and a burst pipe in a vacant house, where nobody notices for days, can cause tens of thousands of dollars in water damage before anyone finds it.
People often ask: "what temperature should I leave my AC on while on vacation in winter?" Switch the system from cool to heat, set it to 55-60°F, and leave it alone. Don't leave it on cooling mode. This sounds obvious, but it's a real thing people do.
Before you leave for the winter, take these steps:
- Turn off the water supply to the whole house.
- Drain the water pipes. Run taps in an interior bathroom and kitchen sink until it's dry.
- Open cabinet doors under sinks. Heated indoor air needs access to those pipes.
- Take out all trash. Stale garbage attracts animals, and animals find ways in.
- Unplug non-essential appliances. Lamps, televisions, game consoles.
- Seal the house as tightly as possible to keep cold and critters out.
What Temperature to Set Air Conditioner When Away in Summer
If you're wondering what temperature to set air conditioner when away in summer, the target range is 78°F to 85°F. That keeps cooling costs down without letting the house get hot enough to damage electronics, warp drywall, or let humidity build to the point where mold becomes a real risk. The 85°F ceiling isn't about comfort - nobody's there to be uncomfortable - it's about protecting the structure and everything in it. Wood expands and contracts with heat. Drywall absorbs moisture. Electronics have operating temperature limits that most people never think about until something fails.
For those asking what temperature to set thermostat when away in summer in a humid region - Florida, the Gulf Coast, the Southeast - stay at 78°F or below. Mold remediation is expensive. The extra cooling cost is not. This is one of those situations where the cheaper-seeming option ends up costing more.
A few things that help keep the house cooler without running the AC harder:
- Close all blinds and curtains before you leave. Sunlight is a major heat source in an empty house.
- If you have storm windows, install them before a long absence.
- Make sure your insulation is adequate - especially in the attic.
For more tips on leaving your home for the summer, check out our summer vacation guide.
What Temperature Should I Leave My AC On While at Work?
This is a completely different scenario from a vacation. If you're searching for what temperature should I leave my AC on while at work, the answer is not 85°F - and the reason matters more than the number itself.
If you let the house get that hot during an 8-hour shift, your AC will run non-stop for hours to cool it back down when you get home. You won't save money. The system will actually consume more energy in that recovery cycle than it would have if you'd just left it running at a slightly elevated setting all day.
The right move is to bump the thermostat 3 to 4 degrees higher than your normal comfort setting. If you keep it at 72°F when you're home, set it to 76°F when you leave for the office. The system gets a break, you save a little on the electric bill, and the house cools down quickly when you return because it hasn't had a chance to fully heat up. Same logic applies in winter - drop it 3-4 degrees below your normal setting while you're at work, not all the way to 55°F.
What Temperature to Leave House When on Vacation
For a standard one-to-two week trip, the rules shift slightly. When deciding what temperature to leave house when on vacation, aim for 80°F in summer and 60°F in winter - tighter margins than a full-season absence, and for good reason.
You aren't draining the plumbing or clearing out the fridge for a short trip. You want a buffer. If a winter storm hits while you're in Cancun, or a heatwave spikes while you're in Maine, that 5-degree cushion is what keeps the house intact until you get back. A full-season absence gives you time to prepare properly. A two-week vacation doesn't.
Can I Leave My House Empty for 2 Months?
Yes - with the right preparation. Two months is long enough that you should treat it like a full seasonal absence, not a vacation, and the preparation list is longer than most people expect.
In winter: set the thermostat to 55°F, turn off the water supply, drain the pipes, and arrange for someone to check the property periodically - not just to look at it, but to actually go inside and verify the temperature is holding.
In summer: set the thermostat to 78-80°F, close all blinds, and have someone check in every few weeks. A smart thermostat with remote monitoring is genuinely worth the investment for a two-month absence, because it lets you catch a problem before it becomes a disaster.
One thing most people don't think about: your home insurance policy. Many policies require a minimum indoor temperature - typically 55°F - for coverage to remain valid on vacant properties. If a pipe bursts and the house was colder than your policy allows, the claim can be denied. That's not a hypothetical. It happens. Check your policy before you leave, not after something goes wrong.
What Temperature Is Too Cold for a Vacant House?
Below 55°F is the risk zone. Pipes in exterior walls and uninsulated spaces can freeze well before the interior temperature drops to 32°F - the 55°F floor exists precisely because the air temperature inside a house can read 55°F on the thermostat while the temperature inside an exterior wall cavity is already below freezing. That gap is where burst pipes live.
If your house has older plumbing or sits in a climate with extreme cold, 58°F is a safer minimum. Some experts in mild climates suggest 45°F is acceptable if the pipes are well-insulated and the water is turned off - but that's a calculated risk, not a recommendation, and it depends heavily on how well you actually know your home's insulation situation.
Does Climate Affect the Ideal Temperature for a Vacant House?
Yes. The 55°F winter floor and 78-85°F summer range are starting points - your local climate determines where in those ranges you should land, and the difference between a dry Colorado winter and a wet Michigan winter matters more than most people realize.
- Winter (cold climate): Set the thermostat to 55°F minimum. In extreme cold climates with older plumbing, 58-60°F is safer.
- Summer (hot/humid climate): Set the thermostat to 78-80°F to prevent mold and protect electronics. In dry climates, 82-85°F is acceptable.
- Mild winter climates: 45°F may be acceptable if pipes are drained and insulated, but this is a risk calculation, not a standard recommendation.
Should the Thermostat Stay Constant in a Vacant House?
Yes. Letting the temperature swing in an empty house creates problems that compound over time in ways that aren't always obvious until you're back home looking at the damage.
In winter, a cold snap can freeze pipes that were fine the day before - the temperature doesn't have to stay below freezing for long to do real damage. In summer, a few days of unchecked heat and humidity can trigger mold growth in walls and under flooring, and by the time you smell it, it's already spread.
A programmable thermostat holds a steady temperature and can make minor adjustments - slightly warmer during winter nights, slightly cooler during summer days - without you having to think about it. That consistency is what protects the house, and it costs almost nothing compared to the alternative.
Additional Steps to Take When Leaving a House Vacant
Getting the thermostat right is step one. But a vacant house has more failure points than just temperature - and most of them are cheap to address before you leave, expensive to deal with after. Run through this list before you lock the door:
- Turn off the water supply: Shut off the main water valve to prevent leaks or pipe bursts.
- Insulate pipes: Wrap exposed pipes in cold climates to prevent freezing.
- Open cabinet doors: Open cabinet doors under sinks so heated air reaches the pipes.
- Unplug appliances: Disconnect non-essential appliances to save energy and reduce electrical risk.
- Change your filters: Change your AC and furnace filters before you go. A dirty filter makes your HVAC work harder and can cause problems while you're gone. Check out our guide to dirty furnace filters and pick up affordable replacement filters before you leave.
- Secure the house: Use light timers, lock windows and doors, and consider a security system.
- Service HVAC systems: Have your HVAC serviced before a long absence if it's due for maintenance.
- Remove perishables: Clear out perishable food to avoid pests and odors.
- Arrange maintenance: Arrange for someone to mow, shovel, and check the property periodically.
None of these take more than an hour. The filter change and the water shutoff are the two most important - skip those and you're rolling the dice on your HVAC system and your plumbing at the same time. It's all worth five minutes of your time before a long absence.
Are Smart Thermostats Worth It for a Vacant Home?
Yes, if you're leaving for more than a few days. The ability to monitor temperature and humidity remotely - and adjust settings from your phone if something looks wrong - is worth more than the purchase price of the device, especially for anyone with a vacation property or a habit of extended travel.
Smart thermostats, like those made by AprilAire, let you check the weather forecast at your property and adjust accordingly. If an unseasonably dry summer day is coming, you can bump the thermostat up a few degrees because you're less worried about humidity. If a cold snap is forecast, you can lower the heat threshold before it hits. That kind of real-time, context-aware control is something a fixed setting can't replicate - and it's the closest thing to actually being there without being there.
Geofencing is a nice feature for frequent travelers, though it's more useful for daily use than for a months-long absence. The cost of a smart thermostat is negligible compared to the cost of a burst pipe or a mold remediation job.
Should You Notify Someone About the House While It's Vacant?
Yes. A trusted neighbor, friend, or property manager who can physically check the house is your best backup - and 'check' means going inside, not just driving by.
Give them your emergency contact information and a clear threshold for when to call. Something like: if the indoor temperature drops below 50°F or rises above 90°F, call immediately.
During summer and winter, temperature swings in a vacant house can cause expensive damage fast, and the difference between catching a problem on day two versus day fourteen is often the difference between a repair bill and a rebuild. Someone who can act quickly is worth more than any smart thermostat.
Frequently Asked Questions
What is the best temperature to leave an empty house?
55°F in winter and 78-85°F in summer. In humid climates, stay closer to 78°F in summer to prevent mold. In mild winter climates with well-insulated plumbing, 45-50°F may be acceptable if the water is turned off.
What temperature is too cold for a vacant house?
Below 55°F is the risk zone for most homes. Pipes in exterior walls can freeze before the interior air temperature hits 32°F. If your home has older plumbing or poor insulation, 58°F is a safer floor.
What temperature should I set my thermostat when I'm at work?
Bump it 3-4 degrees from your normal comfort setting - not all the way to 85°F. Setting it too high means your AC works overtime to cool the house back down when you return, which costs more than the energy you saved.
Can I turn off my HVAC completely when I'm away?
For a short absence, no - turning it off doesn't save energy because the system works harder to recover when you return. For a long absence (months), it may be acceptable if you drain the pipes and have no temperature-sensitive belongings. Check your home insurance policy first - many require a minimum temperature for coverage to remain valid.
What temperature should I leave my house in summer when on vacation?
78-85°F for most climates. In humid regions like Florida, stay at 78°F or below to prevent mold growth. Close all blinds and curtains before you leave to reduce solar heat gain.
Set your thermostat before you leave, change the filter, and make sure someone can check in. For the right filter at the right price, browse our furnace filters. And if you want more detail on seasonal temperature settings, see our guide on the best temperature for your furnace in winter.