Right now in San Francisco, the air is about 67°F, but the model estimates the asphalt under your dog's paws is closer to 110°F — a gap of roughly 43°F, because clear skies are pouring full sun onto every dark surface. That reading puts San Francisco in the caution range, where short, shade-hugging walks are the most a paw should take. Air temperature alone would have told you none of this — the pavement, not the forecast, is what your dog actually stands on.
Across the 11 hours left today, the pavement in San Francisco is projected to top out near 114°F around 2 PM, when the air will be about 68°F — a 46°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, San Francisco sees highs around 68°F and overnight lows near 58°F. That keeps most of the day walkable, though a rare clear, calm afternoon can still warm exposed pavement more than the mild air suggests. As a seasonal rule of thumb, the safest windows are before about 1:00 PM and after about 2:00 PM.
San Francisco 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 September at an average high of 69°F against 56°F in December, a 13°F swing that decides how much of the day belongs to your dog.
San Francisco sits about 5 miles from Daly City, 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. On a day reading this warm in San Francisco, flat-faced breeds like pugs and bulldogs, plus seniors and young puppies with thinner pads, should sit out the heat entirely — subtract about 10°F from any safe threshold for them. If you must cross hot ground, protective booties or a quick coat of paw wax are the only real barrier between paw pads and the asphalt.