Highlights
Depending on your climate, there are pros and cons to covering or not covering your AC unit.
Covering your AC can prevent ice and snow buildup and keep leaves and sticks from getting into the case.
Be on the lookout for rodents and pests who will nest inside a covered AC unit.
If you cover your AC, choose a cover that only covers the top of the unit, not the sides.
The temperatures are dropping, and your outdoor AC unit is probably the last thing on your mind as you crank up the heat and stoke the fire. But a little cold weather maintenance might be what your air conditioning unit needs to withstand the winter months. While it may be tempting to stick a cover on your air conditioner until spring, find out if it’s the best option for your unit.
Should I Cover My AC in the Winter?

The last thing you want is to turn on your air conditioner on the first warm day of spring and find out it doesn’t work. If you’re on a preventative maintenance schedule for your AC in the fall, you’re one step ahead of the game.
As temperatures drop in the winter, you may be concerned about your outdoor condenser freezing—the big box that sits outside your home. Before covering your AC, be sure to review the pros and cons. It may not be the right call and could even cause problems down the road, like rust, mold, and mice infiltrating your unit.
Modern AC condensers are put through rigorous quality control to ensure they can stand up to harsh winter weather. Where you live and the physical location of your condenser both play a role in whether a cover is necessary. In the north, where the condenser may be subjected to extreme snowfall, covering your condenser is a great way to protect the coils inside from ice buildup, heavy snow, and the weight of fallen leaves.
If your condenser is located in a protected spot away from snow and ice, covering it may not be necessary.
Pros of Covering Your AC in the Winter
Helps stop ice from forming on the condenser coils and causing damage
Protects the box from snow accumulation
Protects the condenser from collecting debris, like sticks and leaves
Will keep the condenser clean so it will run better in the spring
Cons of Covering Your AC in the Winter
Moisture can accumulate inside the condenser, causing rust
Pests like mice can nest in a covered condenser
Mold growth can block airflow
Coils could freeze together due to moisture collection
What Kind of Covers Are Available for My AC?
There are covers you can purchase that surround the entire condenser box and others that cover only the top of the unit. AC condenser covers cost between $40 and $150. If you decide to cover your AC during winter, opt for covering the top only.
Covering the top of the AC will deter rodents and other small animals from turning the unit into their new home. It will also block out moisture that causes rust, corrosion, or mold and mildew problems. If you aren’t fussy, you can place a piece of plywood over the top to prevent leaves, acorns, and sticks from falling into the unit.
If you discover that you’ve attracted a family of rodent roommates or that your condenser is full of mold or mildew in the spring, it may be time to call in the pros. An AC repair company near you can assess your unit for damage and make repairs, so you’re not sweating it out through the spring and summer.
Window Unit Air Conditioners
If you use window unit air conditioning, it’s recommended that you store it indoors during the winter. Otherwise, not only can ice collect—which could freeze the coils and cause failure—but they can also let cold air enter the home if left in a window. Store a window air conditioner in the box it came in or another adequately sized box, so dust and dirt won’t accumulate in the unit over the winter.