Right now in St. Louis, the air is about 83°F, but the model estimates the asphalt under your dog's paws is closer to 125°F — a gap of roughly 42°F, because heavy cloud cover is taking some of the edge off the direct sun. That reading puts St. Louis 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 10 hours left today, the pavement in St. Louis is projected to top out near 125°F around 2 PM, when the air will be about 83°F — a 42°F gap between the forecast your weather app shows and the surface your dog walks on. The surface is already coming down, about 15°F over the next three hours, so waiting a little works in your favour here.
In an average August, St. Louis sees highs around 86°F and overnight lows near 69°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 11:00 AM and after about 4:00 PM.
St. Louis 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 88°F against 41°F in January, a 47°F swing that decides how much of the day belongs to your dog.
The nearest city we track is Springfield, IL, roughly 86 miles from St. Louis — 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 St. Louis 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. On a day reading this warm in St. Louis, 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.