How Hot Does Artificial Turf Get? What the Research Shows

Heat is the honest weak spot of artificial turf. On a sunny summer afternoon, artificial turf gets hot: hot enough that bare feet, paws and small children notice. It's worth understanding how hot, and what actually helps, before you turf a sunny play area or dog run.

What the measurements show

Penn State's Center for Sports Surface Research has studied turf heat for years. Some of what it has reported:

• On its research plots during a summer field day, it recorded synthetic turf surface temperatures as high as about 175 °F (about 79 °C). Natural grass rarely reaches 100 °F (about 38 °C), even on the hottest, clearest days.
• Surface temperatures peak on bright, clear, sunny days with low humidity and little haze.
• In lab tests under a heat lamp, every fibre and infill combination tested exceeded 150 °F (about 66 °C). Combined systems differed from each other by no more than about 12 °F, and none clearly beat standard green fibre with black rubber infill.
• Watering cools turf, but only briefly. In its irrigation work, temperatures rebounded quickly once watering stopped, and a few hours later irrigated turf was only slightly cooler than dry turf.

Those figures come from sports turf with infill under strong sun; a home lawn with sand infill on a mild day will be cooler. But the pattern holds: in direct sun, turf runs much hotter than grass.

Why turf gets hot

Grass stays cool because it's alive: it pulls water from the soil and evaporates it through its leaves, like sweating. Turf can't do that. Its fibres and infill absorb sunlight and hold the heat, and there's no moisture to carry it away once a quick rinse has evaporated.

What helps

• Shade. By far the most effective fix. A tree, a pergola, a shade sail or the house's shadow over the main use area changes everything. Plan it in before the turf goes down.
• Timing. Morning and evening are far cooler than mid-afternoon. For daycares and play areas, schedule outdoor time accordingly on hot days.
• Placement. Turf the areas that get afternoon shade; keep real grass or planting in the hottest, most exposed spots.
• A quick rinse before use on a hot day takes the edge off, knowing the effect fades fast.
• Lighter colours and cooler infills help a little. Research suggests product differences are small compared with shade.

What barely helps

Heat-reducing turfs and infill coatings are marketed widely. Some do run somewhat cooler in testing, but none make turf behave like grass in full sun. Treat them as a modest bonus, not a reason to skip shade.

Kids, dogs and pools

• Kids: check the surface with your hand before letting small children play barefoot on a hot afternoon, and give play areas shade. See playground turf.
• Dogs: paws are sensitive. Shade over part of the run and water nearby. See artificial grass for dogs.
• Pools and balconies: turf around a pool or on a south-facing balcony sits in reflected and direct sun. See balcony turf.

Designing a cooler turf yard

The coolest turf yards are planned around the sun. Map where the shade falls at 3 pm in July, from the house, trees and fences, and put the play area or dog run there. Use turf where people and pets actually spend time, and keep the hottest, most exposed corners as planting beds, gravel or real grass. A pergola, shade sail or umbrella over the patio end of the yard covers the spot people use most. Trees take years, but a fast-growing shade tree planted beside a new turf lawn pays back for decades.

Turf next to other surfaces

Turf isn't the only hot surface in a yard. Dark pavers, asphalt and concrete in full sun also get hot, and composite decking can too. Natural grass, mulched planting beds and water features stay coolest. Mixing surfaces, rather than paving or turfing everything, keeps a yard more comfortable on hot afternoons.

A quick heat check

Before kids or pets go out on a hot afternoon, put the back of your hand flat on the turf for several seconds. If you want to pull it away, it's too hot for bare feet and paws. Give it shade, give it time, or rinse it right before use.

Daycares, schools and camps

For child care centres and schools, heat is part of planning outdoor time. Many schedule active outdoor play for mornings in July and August, keep shaded areas over turfed play spaces, and check the surface before children go out on hot afternoons. Licensed centres' own policies on outdoor play in heat apply; turf doesn't change them, but it's a reason to plan shade into any new playground design rather than adding it later. See playground turf.

Heat is also a reason to keep turf away from where hot things happen: barbecues, smokers and fire pits belong on a patio or pavers, with a clear gap to the turf edge.

Reflected sunlight

A separate problem: energy-efficient low-E windows can reflect and concentrate sunlight onto turf, enough to melt lines into the fibres. If you see a narrow scorch mark that moves with the season, a window is usually the cause. Screens, awnings or window films stop it.

Where it matters most in Ontario

Windsor and the southwest have the hottest summers in the province, and south- and west-facing city balconies trap heat. Turf works in both, with shade planned in. See Windsor.