Why a Winter Cover Is an Essential Investment for Your Pool

When the swimming season ends, many pool owners face a familiar question: “Do I really need a cover for winter?” While it’s possible to close a pool without one in some climates, leaving the water exposed risks debris buildup, algae growth, and costly damage. A winter cover helps protect your investment by preserving water quality, reducing maintenance, and making spring opening faster and easier. 

Do You Have to Cover Your Pool in the Winter?

In some climates, you can close a pool without a cover, but leaving the water exposed leads to debris buildup, algae, and potential damage that make spring opening costly and time-consuming. A well-fitted winter or safety cover protects water quality, limits evaporation, reduces chemical loss and heat escape, and makes reopening far easier. While covers aren’t legally required in most areas, they’re strongly recommended for cleaner water, less maintenance, and a smoother, more affordable spring start-up.

Whether or not you should cover depends on a few key factors:

• Climate: In colder regions, a cover helps protect from ice damage and keeps out seasonal debris. In warmer areas, it blocks sunlight that fuels algae growth.
• Pool type & surface: Vinyl and fiberglass pools benefit from less UV exposure and fewer scratches from falling debris. Above-ground pools, in particular, are more exposed to wind-blown leaves and branches without a cover.
• Maintenance habits: If you won’t be testing, treating, or skimming your pool regularly during the off-season, a cover takes on much of that work for you.

Benefits of Using a Winter Pool Cover

• Cleaner water & fewer contaminants: A cover blocks leaves, dust, and wind-blown debris before they sink, rot, or stain.
• Lower chemical and energy use: By limiting sunlight and evaporation, a cover slows chlorine loss and helps stabilize pH and alkalinity. That means fewer chemical top-offs and less surface heat loss.
• Water level maintenance: Physical coverage dramatically reduces evaporation, so you replace less water (and the chemicals in it). Stable levels also protect the tile line and help prevent liner shrinkage.
• Freeze risk reduction: While no cover prevents freezing outright, it shields the surface from wind chill and traps a bit of solar warmth on clear days. Used with proper winterization, this helps protect fittings and finishes.
• Safety (with safety covers): Anchored mesh or solid safety covers create a strong barrier over the water. They add peace of mind for families with kids, pets, or frequent wildlife visitors.
• Surface protection: Blocking UV exposure and keeping abrasive debris out reduces fading and stains, especially on vinyl liners. Over time, that protection helps extend the life of your surface.
• Easier, cheaper opening: Clean, covered water needs less shock, clarifier, and filtration time in spring. You’ll spend more time enjoying the first swim and less time battling algae and stains.

What Happens If You Don’t Use a Winter Cover?

Skipping a winter cover can work in certain mild climates if you’re diligent with maintenance. But for most pools, it invites problems that are usually easy to prevent:

• Algae blooms and cloudy water: Stagnant water plus sunlight creates ideal conditions for algae, leading to a green and murky spring start-up.
• Higher cleanup costs: Expect more shock, clarifier, and filter cycles—and in some cases, a partial drain and refill.
• Surface or liner damage: Debris can leave stains, UV exposure can wear down vinyl, and freeze/thaw cycles may crack grout or tile lines.
• Equipment strain: Extra debris clogs skimmers and makes pumps work harder when you reopen.

If you decide to go cover-free, these steps help reduce the risks:

• Keep water circulating and sanitized: Maintain chlorine and run the pump consistently, especially after storms.
• Trim trees and use leaf nets: Reduce debris before it reaches your pool.
• Test monthly: Check pH, alkalinity, and chlorine. Shock when needed.
• Protect against freezes: Run pumps during cold snaps and insulate exposed plumbing.

When to Cover a Pool for Winter

A good rule of thumb is to close and cover your pool once the water temperature consistently drops below about 60–65°F. Above that range, algae can still grow even under a cover. Below it, your water chemistry becomes more stable, making winter care easier and more reliable.

Timing can vary by region. In warmer climates, many pool owners wait longer before covering, since algae growth slows later in the season. In colder or unpredictable climates, it’s often better to close a little early rather than risk a sudden freeze that could damage tile, fittings, or equipment. When in doubt, cover sooner than later.

How to Cover Your Pool for the Winter

Here’s a general checklist you can use for any pool:

1. Give the pool a thorough clean
   • Brush the walls and vacuum the floor to remove dirt and algae film.
   • Skim the surface to clear out leaves and debris before they sink, decay, and stain.
2. Balance and treat the water
   • Adjust chemistry to winter levels: pH 7.2–7.6, alkalinity 80–120 ppm, and calcium hardness suitable for your pool’s surface (around 200–400 ppm for plaster, 175–225 ppm for vinyl).
   • Add a strong closing shock to eliminate contaminants. Once circulated, add a winter algaecide to keep growth under control.
   • If you have metals in your water, add a sequestrant to prevent surface stains.
3. Lower the water level
   • For in-ground pools, lower the water 4–6 inches below the skimmer or at least below the return jets and plumbing lines so they can be blown out completely.
   • Always double-check your pool cover manufacturer’s recommendations and consider your local climate.
4. Winterize lines and equipment
   • Use an air blower or shop vac to clear water from plumbing lines, then plug them with expansion plugs. Insert a Gizzmo or similar device in the skimmer to absorb ice pressure.
   • Drain pumps, filters, heaters, and chlorinators by removing their plugs.
   • In freeze-prone areas, full drainage and shutdown is safest. “Freeze protection” modes, which keep water moving, are better suited to milder climates.
5. Install the cover securely
   • Safety covers: Tighten straps until springs compress about halfway to two-thirds to provide the right tension.
   • Solid/tarp covers: Secure with water bags (in-ground) or with the included cable and winch (above-ground). The cover should rest evenly on the water with minimal gaps.
6. Set up a cover pump (for solid covers)
   • Place a small submersible pump in the center of the cover to remove rain and snowmelt. Direct the hose so it drains away from the pool.
7. Monitor the cover through winter
   • Check anchors, straps, and water level periodically.
   • For safety covers, let snow melt naturally, as they’re designed to handle the weight. Don’t rake or shovel them.
   • For solid covers, continue pumping water off as it collects to prevent sagging.

Choosing the Right Winter Pool Cover

*Prices are estimates and vary based on pool size, shape, and material quality.

Standard Winter Cover (Tarp)

This is the entry-level, budget-friendly choice. Made of tarp-like polyethylene, it floats on the water’s surface and is secured with water bags (in-ground pools) or a cable and winch system (above-ground).

• Durability: Short lifespan, usually 1–3 seasons.
• Winter Maintenance: Solid covers collect rain and snowmelt, so a cover pump is required. You’ll also need to clear off leaves and debris regularly.
• Safety: Not a safety device—cannot support people or pets and can pose a drowning risk if unmanaged.
• Spring Opening: Keeps out large debris but allows fine silt and dirt to seep in. Expect extra vacuuming and chemical balancing when reopening.

Mesh Safety Cover

Mesh safety covers balance safety, long lifespan, and low upkeep. Made from tightly woven mesh, they’re anchored to the deck and pulled tight across the pool.

• Durability: Built to last, typically 10–15 years with proper care.
• Winter Maintenance: Very low effort. Rain and snow pass through, so no pump is needed.
• Important Note: In snowy regions, allow snow to melt naturally. Do not shovel or brush, as this can damage the fabric.
• Spring Opening: Easier to manage through winter, but fine debris and algae spores still get in. The pool will be full, but water often looks cloudy or green, requiring more cleanup and chemicals.

Solid Safety Cover

This cover combines the safety of mesh with the cleaner spring opening of a tarp. Made of heavy-duty vinyl, it’s anchored taut across the deck like a mesh cover.

• Durability: Lifespan of about 6–11 years. Slightly shorter than mesh due to heavier material wear.
• Winter Maintenance: Like tarps, rain and snow collect on top. A cover pump is required to keep water from pooling and adding too much weight.
• Spring Opening: The cleanest option. By blocking 100% of sunlight, debris, and water, it keeps the pool nearly pristine; meaning less work, fewer chemicals, and a faster opening in spring.

For a detailed comparison, check out our in-depth breakdown of Pool Safety Covers vs. Winter Pool Covers.

Is a Winter Pool Cover Necessary? - Frequently Asked Questions

Should pool equipment be covered during winter too?

• Generally, no. Pumps, filters, and heaters are designed to be outdoors, and tightly wrapping them can trap moisture that leads to rust or mold. If you want extra protection for a heater, choose a breathable top cover or mesh-sided shield, and always winterize the equipment first.

Should I cover my pool heater in the winter?

• Only with breathable protection, if at all. Fully enclosing a heater can trap moisture and cause corrosion. If you do cover it, use a design that shields the top while allowing airflow through the sides. Never run the heater while it is covered.

Does pool water evaporate under a winter cover?

• A cover greatly reduces evaporation. Solid covers block nearly all of it, while mesh covers still slow evaporation significantly, helping maintain water levels and chemistry stability.

Will a winter cover keep my pool from freezing?

• No, a cover alone cannot prevent freezing. While it reduces wind chill and heat loss, true freeze protection comes from proper winterization, including lowering the water level, blowing out and plugging lines, and using freeze-protection settings in milder climates.

Can I leave my above-ground pool up during winter?

• Yes, most above-ground pools are designed to stay up year-round if properly winterized. The exception is soft-sided or temporary pools, which may require draining and storage in areas with severe winters.

Can I use a tarp instead of a pool cover?

• You can, but it is a compromise. A standard tarp is not a safety device, breaks down faster, and requires careful weighting, while a purpose-built winter or safety cover is safer, more durable, and better for protecting your pool.

When should I cover my pool to avoid algae?

• Cover your pool once water temperatures consistently drop below about 60–65°F. At that point algae activity slows, chemistry stabilizes, and your cover can do its best work.

Should I remove snow and water from the cover?

• For solid covers, wait for snow to melt and then use a cover pump to remove the water that collects on top. For safety covers, never attempt to remove snow—these covers are engineered to hold heavy loads, and trying to clear them can tear the fabric, damage straps, or void the warranty.

How much does it cost to cover a pool?

• Standard winter tarps for above-ground pools typically range from about $75 to a few hundred dollars. Custom safety covers for inground pools usually fall into the low thousands depending on size and shape, but the investment often pays off by reducing spring cleanup and long-term repair costs.

Here are some additional resources for swimming pool covers: 

• How to Close an Inground Pool
• How to Close an Above Ground Pool
• How to Winterize a Pool
• Pool Covers: The Differences, Benefits & How to Buy
• The Ultimate Guide to Swimming Pool Maintenance