The short answer: below about 19°C (66°F) you’re fine for most dogs. From 20–23°C, start shortening walks and watching flat-faced and heavy-coated breeds. At 24–27°C, walk only at dawn and dusk and keep it gentle. Above 28°C (82°F), most dogs should skip the walk entirely and do something cool indoors instead. These are air temperatures in shade — direct sun and humidity push every number lower.
Heat is one of the few walking risks that kills quickly, so it’s worth being slightly over-cautious.
The temperature ladder
Use this as a default, then adjust down for your specific dog (see below).
- Under 19°C (66°F). Normal walking for almost all dogs.
- 20–23°C (68–73°F). Fine for most, but shorten sessions for brachycephalic, double-coated, senior, overweight, and very young dogs. Carry water.
- 24–27°C (75–81°F). Walk early morning or after sunset only. Keep the pace easy, stick to shade and grass, cut the distance. High-risk breeds should stay home.
- 28°C+ (82°F+). Skip the walk. Do indoor enrichment, a paddling pool, or a cool sniff session in the shade. No dog needs a walk badly enough to risk heatstroke.
Humidity matters as much as the number. Dogs cool themselves by panting, which only works if water can evaporate. In humid air it can’t, so a muggy 24°C is more dangerous than a dry 26°C.
The seven-second pavement test
Air temperature isn’t what burns paws — surface temperature is, and asphalt runs far hotter than the air above it. On a 25°C day, tarmac in direct sun can reach 50°C or more, hot enough to blister a paw pad in under a minute.
The test is simple: press the back of your hand flat to the pavement for seven seconds. If you can’t hold it there comfortably for the full seven, it’s too hot for paws. Walk on grass, go at a cooler hour, or don’t go.
Pavement at 52°C can cause skin damage in roughly 60 seconds of contact. The air can feel pleasant while the ground is dangerous — always check the surface, not the forecast.
The breeds that overheat first
Some dogs are in trouble well before the thermometer looks worrying. Be far more conservative if your dog is:
- Flat-faced (brachycephalic) — French Bulldogs, Pugs, Bulldogs, Boxers. Their shortened airways make panting inefficient, so they can’t shed heat. A French Bulldog can be in real danger on a day a Labrador handles fine.
- Double-coated / heavy-coated — Huskies, Malamutes, Bernese, Newfoundlands. Built for cold, poorly built for heat.
- Senior, overweight, or very young. Less efficient temperature regulation across the board.
- Dark-coated dogs in direct sun, which absorb more radiant heat.
Do not shave a double-coated dog to “cool it down” — the coat insulates against heat as well as cold and protects against sunburn. Provide shade and water instead.
Spotting heatstroke
Know the signs, because early action saves lives. Watch for: heavy, frantic panting; thick drooling; bright red gums; wobbliness or stumbling; vomiting or diarrhoea; collapse. If you see these, move the dog to shade, wet it with cool (not ice-cold) water, offer small drinks, and call your vet immediately. Heatstroke is a genuine emergency — minutes matter.
What to do instead on a hot day
A skipped walk isn’t a failed day. Sniff games indoors, a frozen stuffed Kong, a shallow paddling pool, gentle training, or a scatter-feed across a cool tiled floor all spend a dog without the risk. Our rainy-day routines piece doubles as a heatwave plan — the indoor-substitute maths is the same.
If you want a baseline for how much your dog needs on a normal day — the figure you’re trimming down from in the heat — the walking calculator sets it by breed, age, and energy.
The rule of thumb to carry: when in doubt on a hot day, do less. Dogs hide discomfort well, and by the time a dog looks distressed in heat, it’s often already in trouble.
For the wider citation list behind walkingdog.io, see /sources/.