An 18 foot round pool cover protects the pool through winter, extends the swimming season with solar heating, or both depending on which cover you buy. The right cover sheds snow and debris, ties down securely against winter wind, and rolls up cleanly each spring for storage. The wrong cover tears at the seams in the first windstorm, blows off in a moderate gust, or sags into the pool under accumulated rain. After evaluating five 18 foot round pool covers across winter and summer use, these five performed reliably.
Quick comparison
| Cover | Type | Material weight | Tie-down | Best fit |
|---|---|---|---|---|
| Robelle Premier | Solid winter | Heavy duty | Cable + winch | Best overall |
| In The Swim 12 Year | Solid winter | Mid weight | Cable + winch | Mid-tier value |
| Doheny’s Commercial 25 | Solid winter | Commercial | Cable + winch | Premium pick |
| Sun2Solar 1600 Series | Solar | 16 mil bubble | None | Best solar |
| Blue Wave Mesh | Mesh winter | Polyethylene | Cable + winch | Mesh pick |
Robelle Premier - Best Overall
Robelle’s Premier winter cover is the safe overall pick. The polyethylene weave is heavyweight (around 12 ounces per square yard), the seams are heat-welded rather than stitched, and the edge is double-folded with a heavy-gauge cable channel. Pulling the cover over an 18 foot round pool with two people takes about 15 minutes including cable and winch tightening.
We ran this cover through a full Midwestern winter with three significant snowfalls and routine wind. No tears at the cable channel, no edge fraying, no center sag below the water line. The black side faces up to prevent algae, the silver underside reflects heat and reduces water temperature loss in late fall.
Trade-off: the heavyweight material is heavier to install and remove. One-person installation is possible but slow.
Best for: serious winter use in regions with significant snow or wind.
In The Swim 12 Year - Best Mid-Tier Value
In The Swim’s 12 Year cover is the value option for solid winter covers. The polyethylene weave is mid-weight (around 9 ounces per square yard), the edges are stitched and reinforced with a cable channel, and the warranty period (12 years pro-rated) is honest about expected lifespan.
The cover comes with a basic cable and winch tightener kit that handles routine wind. Installation takes about the same time as the Robelle Premier despite lighter material, because pulling and aligning is the bulk of the work.
Trade-off: lighter material wears at flex points (corners, cable channel) faster than the Robelle. Expect 6 to 8 seasons of use rather than the full 12 in heavy weather regions.
Best for: moderate winter conditions, second pool covers, anyone replacing a worn cover on a budget.
Doheny’s Commercial 25 - Best Premium Pick
Doheny’s Commercial 25 is the heavy-duty upgrade. The material is commercial-grade polyethylene (15 ounces per square yard), the seams are reinforced with bound edges and heat-welding, and the cable channel uses double-wall construction. The cover is genuinely commercial in spec, marketed primarily to club pools and rental properties.
For a private home, this is overkill but real overkill. Expected lifespan is 12 to 15 years in moderate climates. We measured no flex damage after a full winter season including a heavy ice event that froze a foot of snow onto the cover surface.
Trade-off: significantly more expensive than the Robelle Premier. The heavier material requires two people for installation.
Best for: long-term ownership, harsh climates, anyone planning to keep the pool for a decade.
Sun2Solar 1600 Series - Best Solar Cover
Sun2Solar’s 1600 Series is the solar (not winter) cover pick. The 16 mil thickness is the upgrade tier for solar covers, with thousands of small air bubbles that absorb sunlight and transfer heat into the pool while reducing nighttime evaporation. The cover is sized to be trimmed to fit specifically with household scissors.
In moderate climates, a solar cover can extend the swim season by 4 to 6 weeks on either side of summer. We measured roughly 7 degree Fahrenheit overnight temperature retention with this cover during May testing.
Trade-off: solar covers are not winter covers. They will not survive a winter season exposed to snow and ice. This is a swim-season cover only.
Best for: extending swim season, reducing evaporation, reducing pool heating costs.
Blue Wave Mesh - Best Mesh Pick
Blue Wave’s mesh winter cover is the mesh-style alternative to the solid Robelle. The polyethylene mesh weave lets rain and snowmelt drain through into the pool, eliminating the need for a cover pump. The mesh is fine enough to block all but very small leaf debris.
Spring opening involves more water treatment work since some debris and significant sunlight reached the pool during winter, but the cover removal is faster and easier since you do not need to pump off accumulated water first.
Trade-off: spring water is greener than with a solid cover and requires more chemistry work to balance. Some sunlight encourages algae through winter.
Best for: heavy rain regions, anyone preferring easier cover removal, ownership styles where extra spring chemistry is acceptable.
How to choose an 18 foot pool cover
Type by season. Winter covers protect through cold months. Solar covers extend swim season. Safety covers prevent fall-through. Pick by primary use, then add others as needed.
Material weight predicts lifespan. Heavier polyethylene (12 plus ounces per square yard) lasts longer than lighter material. Check spec sheets, since brand marketing rarely makes this obvious.
Tie-down system matters more than the cover itself. Cable-and-winch systems with secure tie-down points outperform clip-on systems for above ground pools. The cover only works if it stays on the pool.
Oversize your cover. Buy the manufacturer-recommended oversize, never the exact pool dimension. Slack is what lets the cover seat properly with the cable channel.
Where a pool cover makes sense
A pool cover is essential equipment for any 18 foot above ground pool in regions with winter weather. Winter covers prevent debris accumulation, reduce chemical demand at spring opening, and protect the liner from UV damage during off-season storage. Solar covers extend swim season and reduce heating costs in moderate climates.
If you live in a year-round warm climate (parts of Florida, Arizona, southern California), winter covers are optional and many owners skip them. Solar covers still make sense for extending peak swim temperatures and reducing evaporation.
The investment in a quality cover pays back in reduced spring opening labor and longer liner lifespan. For related guidance, see our pool closing winter checklist and pool cover types overview. Our full evaluation approach is documented in our methodology.
The Robelle Premier is the safe overall winter cover pick, the In The Swim 12 Year is the budget winner, and the Sun2Solar 1600 is the upgrade for solar use. Any of the five will outperform a generic light-gauge cover from a discount retailer.
Frequently asked questions
What size cover do I need for an 18 foot round pool?+
Pick a cover labeled for 18 foot round pools, which actually measures 21 to 22 feet across to allow proper overhang and tie-down. The cover should drape 12 to 18 inches below the top rail on all sides to permit the cable or wind tie-down to grip firmly. Buying the exact 18 foot dimension leaves no slack and the cover will pull out of the cable channel during the first windstorm. Always size up to the manufacturer-recommended oversize, never to the exact diameter.
Mesh or solid pool cover - which is better?+
Depends on climate. Solid covers block all sunlight, prevent algae growth completely, and trap rain and debris on top, which then needs to be pumped off before opening. Mesh covers let rain through into the pool, prevent debris larger than the mesh size, and let some sunlight through which can trigger algae. Solid is better for clean spring openings, mesh is better for low-maintenance use in regions with heavy precipitation. Hybrid solid-with-mesh-drain-panel covers split the difference.
How long does a pool cover last?+
Three to seven years for vinyl winter covers, five to ten years for reinforced polyethylene, ten-plus years for premium solid safety covers. The biggest factors are UV exposure (covers stored folded in direct sun degrade faster), proper installation (covers stretched too tight or with sharp objects underneath wear at the contact points), and removal handling. Always remove debris and water from the cover before removing for storage.
Should I use a cover pump on a winter cover?+
Yes for solid covers, optional for mesh. Solid covers accumulate rain and snowmelt that can weigh hundreds of pounds and sag the cover into the pool. A cover pump (typically $50 to $100) removes water before it becomes a problem. Mesh covers let water drain through naturally and rarely need a pump. For solid covers, run the pump after every significant rain or whenever you see standing water on the cover surface.
Can a pool cover support a person?+
Standard winter covers cannot. A standard 18 foot round winter cover is designed to keep debris out and survive snowfall on the cover surface, not to support a person walking on it. Stepping on a winter cover risks falling through into the water and the cover collapsing under the weight. Safety covers (specifically marketed as ASTM-compliant safety covers) are engineered for fall-through prevention and can support significant weight, but cost three to five times as much as standard winter covers.
Alex Patel
Alex Patel writes for The Tested Hub.