Right now in Durham, the air is about 75°F, but the model estimates the asphalt under your dog's paws is closer to 75°F — the surface and air have nearly converged because the pavement is shedding the day's stored heat after dark. That reading puts Durham in the clear for an ordinary walk. Air temperature alone would have told you none of this — the pavement, not the forecast, is what your dog actually stands on.
Across the 19 hours left today, the pavement in Durham is projected to top out near 131°F around 2 PM, when the air will be about 88°F — a 43°F gap between the forecast your weather app shows and the surface your dog walks on. Today breaks into 2 separate safe stretches rather than one continuous window, so missing the first does not cost you the day.
In an average August, Durham sees highs around 88°F and overnight lows near 70°F. Even at those moderate highs, a dark surface in direct sun can run 40–60°F hotter than the air, which is enough to tip midday walks into the caution range. As a seasonal rule of thumb, the safest windows are before about 10:00 AM and after about 5:00 PM.
Durham loses its all-day safe window in 5 months of the year — May through September — and August is one of them. The year peaks in July at an average high of 91°F against 52°F in January, a 39°F swing that decides how much of the day belongs to your dog.
Durham sits about 15 miles from Cary, close enough that the two usually run within a degree or two of each other — if your walk crosses between them, either page answers the question. Street-level conditions still differ more than city-level ones do: a shaded side street and an open parking lot half a block apart can be twenty degrees apart underfoot.
Whatever the number says, confirm it with your hand: press the back of it flat on the pavement for seven seconds. If you can't hold it there, neither can your dog. Conditions in Durham are on the gentler side right now, but keep the same habits: water before and after, grass over asphalt, and a close eye on flat-faced breeds, seniors, and puppies, who overheat and burn sooner than a healthy adult dog.