A patio that looks inviting in April can be too hot to cross barefoot by July. Long, sunny Sacramento summers push surface choice up the list when planning outdoor space. Cooler patio materials help, but shade usually does more than any single product, and the two work well together.
Specific surface temperatures depend on sun angle, time of day, wind, moisture and the exact product, so no number from a sales sheet will match your yard. The research below explains why some surfaces stay cooler and what to test before you buy.
Why Some Surfaces Get Hotter
Color and reflectance drive most of the difference. Lawrence Berkeley National Laboratory’s Heat Island Group explains on its cool pavements page that dark pavements get hot in the sun because they absorb 80 to 95% of sunlight. Surfaces that reflect more sunlight stay cooler.
The same page lists ways to raise reflectance, such as reflective aggregate, a reflective or clear binder or a reflective surface coating. Those methods come from street and parking lot research. Many of the same ideas, such as lighter colors and lighter aggregate, carry over to home patios.
Hot paving affects more than your feet. LBNL notes that hot pavements warm the local air and can raise the temperature of stormwater runoff.
How Common Materials Compare
The lab gives reflectance ranges for two common pavements. New cement concrete has a solar reflectance of 30 to 50%. Asphalt starts near 5% when new. Those figures help explain why a gray concrete slab often feels cooler than a dark asphalt path in the same sun.
Pavers and natural stone come in many colors and finishes. Light colored units generally reflect more sun than dark ones, though actual values vary by product. Ask the supplier whether a solar reflectance value has been measured for the paver you are considering.
Permeable surfaces add another factor. A UC Statewide IPM page on landscape design and water quality recommends porous options such as flagstone, interlocking pavers and pervious concrete for walkways and patios. They let water soak in, which helps with runoff.
Surfaces Change With Age
Reflectance does not stay fixed. LBNL says concrete tends to get darker with tire and grease stains as it ages, dropping from 30 to 50% solar reflectance when new to about 20 to 35% when aged. Asphalt lightens as its binder oxidizes and more aggregate shows, rising from about 5% to 10 to 20%.
On a patio, that means a light surface will not stay as light as the showroom sample. Dirt, leaf stains, sealers and wear all shift color over time. Plan for some darkening, and keep surfaces clean if heat matters to you.
Shade Does the Heavy Lifting
A surface in shade gets no direct sun to absorb. Trees, pergolas, shade sails and the house itself can all block the hottest afternoon sun.
Where the patio sits matters. Afternoon sun from the west reaches a patio during the hottest part of the day. The article on picking seating areas with morning or afternoon shade covers how to read your site.
Trees take time to grow, so plan for both now and later. Leave room near the patio for a future shade tree with adequate soil and space, and check the mature size before planting.
Reflected Heat and Nearby Plants
Hot surfaces affect the garden around them. The UC Master Gardener statewide blog post on gardening in extreme heat warns that plants near walkways, patios and other structures that radiate heat are often the first to show heat stress and may need extra water.
That has two lessons for patio planning. Choose tough, heat tolerant species for a sunny patio edge. Expect those beds to need more attention in summer than beds farther from the paving.
Questions to Ask Suppliers
Product details make comparison easier. Before choosing among cooler patio materials, ask each supplier a few plain questions and write the answers down.
- Has the solar reflectance of this product been measured, and what was the value?
- Does the color run through the whole unit or sit only on the surface?
- How does the finish look after several years outdoors?
- Does any sealer change the color or sheen?
- Can full size samples be borrowed for testing?
Answers vary by maker, and some suppliers may not have measured values. The questions still help you compare products on the same terms. Combine the answers with your own sample test before making a final choice.
Budget and Tradeoffs
Cooler surfaces are one goal among several. Durability, drainage, slip resistance, look and cost all matter too. LBNL research also notes that cool pavement materials usually need more energy and carbon to make than conventional ones, with concrete that uses much less portland cement as an exception. That finding came from city scale studies, yet it is a reminder that every choice carries tradeoffs.
Sometimes a modest shade structure over a standard surface gives more comfort than a specialty product in full sun. Price both approaches before deciding.
Barefoot Comfort and Use
Think about how the patio is used. A dining area under a pergola faces different demands than a pool deck where people walk barefoot. Poolside areas raise comfort and slip questions together. See choosing pavers for poolside foot traffic and how concrete finishes change slip resistance.
Texture affects comfort as well as grip. A rough finish may feel different underfoot than a smooth one, and both can get hot. Choose finishes for safety first, then compare colors within the safe options.
Testing Cooler Patio Materials at Home
Samples tell you more than catalogs. Ask for full size samples of each paver, stone or concrete finish you are considering. Set them side by side in full sun on a hot afternoon. After a few hours, compare how each one feels to the back of your hand, and use an infrared thermometer if you have one.
Leave the samples out for several days. Check them in morning, midday and late afternoon.
Write down what you find. A short table of sample, color, time and feel helps you compare without relying on memory.
Putting It Together
- Plan shade first, from trees, structures or the house.
- Favor lighter colors where sun hits the surface.
- Expect surfaces to change color as they age.
- Consider permeable options for runoff.
- Pick heat tolerant plants for beds along the edge.
- Test samples in your own sun before buying.
For related heat questions, read why artificial grass gets hot in full sun. More guides sit in the hardscape planning category.