Right now in Portland, the air is about 65°F, but the model estimates the asphalt under your dog's paws is closer to 65°F — the surface and air have nearly converged because heavy cloud cover is taking some of the edge off the direct sun. That reading puts Portland 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 17 hours left today, the pavement in Portland is projected to top out near 89°F around 4 PM, when the air will be about 68°F — a 21°F gap between the forecast your weather app shows and the surface your dog walks on. The surface is holding roughly flat over the next three hours, so there is no meaningfully cooler hour coming soon — choose shade and grass rather than waiting it out.
In an average August, Portland sees highs around 77°F and overnight lows near 63°F. Those are forgiving numbers, but don't let them lull you — a sunny, still afternoon can still heat dark asphalt far above the air, especially for low-riding or short-coated dogs. As a seasonal rule of thumb, the safest windows are before about 1:00 PM and after about 2:00 PM.
Portland loses its all-day safe window in 3 months of the year — June through August — and August is one of them. The year peaks in July at an average high of 80°F against 34°F in January, a 45°F swing that decides how much of the day belongs to your dog.
The nearest city we track is Manchester, roughly 76 miles from Portland — far enough that its reading is no substitute for this one. Sun angle, humidity and cloud cover can all differ across that distance, which is why this page models Portland on its own coordinates.
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 Portland 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.