Is the ground too hot for dog paws in Phoenix?
Pavement in Phoenix has been measured at 155 °F while the air was 105 °F, and concrete in shade came in below the air. What the agencies publish, and what they do not.
Short answer
The ground is usually much hotter than the air, and shade changes that more than anything else. On one Phoenix afternoon the asphalt measured 155 °F and sunlit concrete 140 °F while the air was 105 °F, but concrete in shade measured 93 °F, twelve degrees below the air. No agency publishes a surface temperature at which a paw burns, so the published advice is to test the surface by hand before you walk, and to walk in the early morning rather than the afternoon.
The mistake people make about hot pavement is thinking of it as a warm version of the same surface. It is not. Asphalt in the sun is a different material from asphalt in the shade, by fifty degrees or more, and the number that matters to a dog is the surface, not the air the weather app is reporting.
There is something else worth saying before any of the figures, because it shapes everything below. No agency publishes a surface temperature at which a paw burns. There is an official climate normal for the air, and an official heat index, and an official air-quality index. There is no official pavement index, in Phoenix or anywhere else. What exists instead is a set of measurements from named studies and a set of field tests published by agencies and veterinary bodies, and this page keeps those two things separate.
What the ground measures while the air is at 105 °F
Surface readings from one Phoenix-area afternoon, sorted from coolest to hottest. Shade is not a small correction on this chart; it is the whole difference between the top row and the bottom one.
Sources for the five readings, top to bottom: grass in shade and grass in sun are from the University of Georgia Cooperative Extension chart, taken at 2 p.m. with the air at 95 °F; concrete in shade, concrete in full sun and asphalt in full sun are Arizona State University Arizona State Climate Office measurements taken in the Phoenix area on one afternoon with the air at 105 °F. The Georgia chart is here because it is the only set on this page that measured grass and paving at the same hour. This chart compares surfaces, not days.
Shade is the whole answer
Concrete in shade measured 93 °F. The air at the same moment measured 105 °F. That is the only paved surface in the Phoenix set that came out cooler than the air, and it is twelve degrees below it.
Asphalt in full sun measured 155 °F. The two surfaces are a few feet apart and 62 degrees apart in temperature, and the difference between them is a roof, a wall or a tree. Nothing else in this article changes a number by anything like that margin.
Which is why the useful version of this question is not “is it too hot today” but “which way does the walk go”. A route that puts the dog on the shaded side of a wall for ten minutes is a different route from one that puts it on open asphalt, at the same air temperature, on the same afternoon.
The pavement tests, and which one has a source
Three versions of the same check circulate. Two of them are published by somebody.
Seven seconds: Maricopa County, adapted from the Arizona Humane Society. Place your bare foot, or the back of your hand, on the pavement for seven seconds. If it is too hot for you, it is too hot for pets too.
Ten seconds: the American Kennel Club. Place your hand comfortably on the pavement for ten seconds. If it is too hot for your hand, it is too hot for your dog’s paws.
Five seconds: no publisher. A five-second version circulates widely online. This site could not find any veterinary body or agency that publishes it, and does not use it.
Both published versions are analogies rather than measurements: they assume human skin and a dog’s pads respond similarly enough for the comparison to warn you, and no study on this page tests that directly. That is a real limit, and it is still a better test than a temperature read off a phone, because it measures the surface you are actually standing on rather than the air two metres above it.
Before the walk: what the published guidance points at
This is a checklist of things an agency or a study actually names. It is not veterinary advice, and it is not a substitute for asking a vet about your own animal.
- Test the surface you are about to walk on, with the seven-second or ten-second check, in the sun and not in the shade of your own body.
- Walk in the morning. The Phoenix burn study found asphalt hot enough to burn between 9 a.m. and 7 p.m.
- Treat the middle of the day as closed. The same study measured a second-degree burn in 35 seconds between 10 a.m. and 5 p.m.
- Choose the shaded side of the street. Concrete in shade measured 93 °F against 155 °F for asphalt in sun on the same afternoon.
- Cross asphalt rather than walking along it. The hottest surface in the Phoenix set was also the most common one underfoot.
- Check the route home, not just the route out. The surface is coolest before about 9 a.m. and hottest in the hours either side of 3 p.m., so an outbound walk at eight can return at nine-thirty into a different street.
- Ask a veterinarian about your own animal. Age, coat, weight and existing conditions are the vet’s judgement to make, not a page’s.
Two things are deliberately missing from that list. The first is a temperature threshold, because no agency publishes one. The second is anything about what to do if a paw has already been burned: that is a veterinary question, and this page has no business answering it.
What the Phoenix burn study measured
The one piece of research on this page that was carried out in Phoenix is the one about burns rather than about paws.
Harrington and colleagues, writing in Annals of Emergency Medicine in 1995, measured pavement temperatures in the city and matched them to burn patients at Maricopa Medical Center. Their findings are about hours rather than degrees, which is why the checklist above is written as a schedule:
- Asphalt was hot enough to cause burns between 9 a.m. and 7 p.m.
- It was hot enough to cause a second-degree burn in 35 seconds between 10 a.m. and 5 p.m.
It is worth being precise about what that study is. It measured human patients, not dogs. It is cited here because it is the only pavement-burn research this site could find that was carried out in Phoenix, and because the hours it identifies are the hours the same pavement is underfoot. It is not a study of canine pads, and it does not claim to be.
The same surfaces somewhere cooler
The Georgia chart is useful because it measured grass and paving in the same hour, which the Phoenix set did not. Its afternoon air was 95 °F, ten degrees milder than the Phoenix afternoon above.
| Surface | 2 p.m. reading |
|---|---|
| Grass, shade | 91 °F |
| Air | 95 °F |
| Grass, sun | 105 °F |
| Cement, sun | 125 °F |
| Red brick, sun | 135 °F |
| Blacktop, sun | 140 °F |
The pattern is the same one, at lower numbers. Grass in shade sits below the air, grass in sun sits at it, and every paved surface runs above it, with the blackest and most textured surface running hottest. Brick at 135 °F is a reminder that this is not only an asphalt problem: a brick patio in a Phoenix yard is in the same family as the pavement.
Two more figures from the site’s own tool are worth knowing for a Phoenix yard: bare soil in sun is estimated at 135 °F when the air is 105 °F, and artificial turf, which several studies put hotter than asphalt, carries a figure of its own on the Pavement & Paw Check page with its source attached.
Where this page stops
This article collects published measurements and published tests. It does not diagnose anything, it does not describe what a burn looks like, and it does not tell you what to do about one. If you are worried about an animal, that is a veterinarian’s call and worth making rather than waiting out.
The practical output of everything above is a time and a surface. The Pavement & Paw Check turns an air temperature and a sun-or-shade choice into a surface figure, and the Heat-Safe Hours Planner does the same thing for the day as a whole, which is how the two decide between them which hours a walk belongs in. The parked-car article covers the other enclosed surface a dog ends up on, and it arrives at the same conclusion by a different route: the number is worse than people assume, and it gets there faster.
- Maricopa County: “Protect Your Pet From the Heat”, adapted from the Arizona Humane Society
The seven-second pavement test, in the county’s own wording, and its framing of hot pavement as a pet heat hazard.
- Arizona State University, Arizona State Climate Office: urban heat island surface temperature measurements, Mesa, Arizona
The Phoenix-area surface readings in the chart: 155 °F asphalt, 140 °F concrete in sun and 93 °F concrete in shade, all measured in the same afternoon with the air at 105 °F.
- University of Georgia Cooperative Extension: “How Hot Does Pavement Get?”
The two grass readings and the four paved surfaces at a single 2 p.m. hour with the air at 95 °F, used in the comparison table.
- Harrington WZ et al. “Pavement Temperature and Burns: Streets of Fire.” Annals of Emergency Medicine 1995;26(5):563–568
The hours Phoenix asphalt was measured hot enough to burn, and the 35 seconds it took to produce a second-degree burn during the hottest of them. Measured on people, not on dogs.
- American Kennel Club: veterinary guidance on hot pavement and dog paws
The ten-second version of the hand test, quoted here as the second published version of the same check.