At 25°C, asphalt hits 52°C. At that temperature, paw pads burn in 60 seconds. Here's what you need to know about summer in Toronto with a dog.
By Onslow's Team · Updated August 13, 2026
Before you go out
Put in today's temperature and humidity. Both are on any Toronto weather app.
HIGH risk
Too hot for a walk.
Quick bathroom breaks only.
| At 75% humidity | Risk | What to do |
|---|---|---|
| Under 7°C | Low | Normal walks, bring water. |
| 7–23°C | Moderate | Shorter walks, stick to shade and grass. |
| 24–34°C | High | Quick bathroom breaks only. |
| 35°C and up | Dangerous | Stay indoors, AC if possible. |
Put the back of your hand flat on the pavement. If you can't hold it there for 7 seconds, it's too hot for your dog's paws.
At 25°C air
52°C
Asphalt surface. Paw pad damage starts.
At 31°C air
62°C
Burns in under a minute.
Grass stays around 38°C on a 25°C day. Light concrete is next coolest. Black asphalt is the worst surface by far.
The 7-second rule
Back of your hand on the pavement. 7 seconds. If it burns you, it burns them. Test it every time before you walk.
Toronto's average July humidity is 77–82%. That's the hidden factor. Dogs cool down by panting, and panting doesn't work when the air is soaked.
Safe walking windows in July/August
Best: before 8am and after 8pm.
Maybe: 8 to 10am and 6 to 8pm (test the pavement).
No: 10am to 6pm on anything above 25°C.
During heat warnings (30°C+ / humidex 40°C+), limit walks to bathroom breaks only.
A dog's normal body temperature is 38–39°C. Heatstroke starts at 41°C. At 43°C, organs start failing.
| Stage | Signs | What to do |
|---|---|---|
| Early warning | Heavy panting, excessive drooling, bright red gums | Move to shade, offer water, stop exercising |
| Getting worse | Vomiting, diarrhea, stumbling, acting confused | Start cooling (cool water, fan), call vet |
| Emergency | Collapse, seizures, purple or blue gums | Cool immediately, drive to emergency vet NOW |
Heatstroke first aid: do this immediately
Move them to shade or AC immediately. Apply cool water (NOT ice water, that traps heat). Put them near a fan. Offer small sips of cool water.
Then get to an emergency vet. Even if they seem to recover, internal organ damage may have already started.
| Outside | 10 min | 30 min |
|---|---|---|
| 21°C | 32°C | 40°C |
| 27°C | 37°C | 46°C |
| 32°C | 43°C | 51°C |
Cracking the windows reduces the temperature by maybe 1–2 degrees. Dogs can get heatstroke in a hot car in 15 minutes. Fifteen.
Ontario law: up to $130,000 fine
Under the PAWS Act, police and animal welfare inspectors can legally break into your car to rescue your dog. First offence: up to $130,000 and 2 years in prison. Second offence: up to $260,000.
If you see a dog in a hot car, call 911 for immediate danger. You can also report animal distress to the Ontario Animal Protection Call Centre at 1-833-9-ANIMAL.
Blue-green algae can kill a dog within hours
If the water looks green or scummy, keep your dog out completely. No exceptions. Read our full blue-green algae guide for hotspots and symptoms.
High-risk breeds: flat-faced dogs overheat 6–14x faster
English Bulldogs are 14x more likely to get heatstroke than Labs. French Bulldogs 6x, Pugs 3x. Overweight dogs of any breed are 1.5x more at risk. If your dog is flat-faced, overweight, or thick-coated, cut walk times in half and skip anything above 25°C. Don't shave double-coated breeds; the undercoat insulates against heat.
Cooling vests: Wet with cool water, wring out, put on the dog. Re-wet them regularly because they stop working when dry.
Frozen treats: Freeze low-sodium chicken broth or mashed banana in ice cube trays or Kongs.
Elevated dog beds: Air circulates underneath. Way cooler than lying on the floor.
Kiddie pool in the shade: Cheap, effective, dogs love it.
Wet towels: Drape a cool damp towel over your dog. But replace it frequently. A warm wet towel traps heat and makes things worse.
Cool water, not ice water
Standard first-aid advice is to use cool water, not ice water. The concern is that very cold water constricts blood vessels and may slow cooling. Some recent veterinary research supports cold water immersion for severe heatstroke, but cool water is the safer default. Either way, get to a vet.
Use the checker above. Enter today’s temperature and humidity. In Toronto, a typical 27°C day with 80% humidity is already in the high-risk zone. Before 8am and after 8pm are the safest windows in July and August.
Put the back of your hand on the pavement. If you can’t hold it for 7 seconds, it’s too hot. At 25°C air temperature, black asphalt reaches 52°C. Stick to grass, shaded paths, or light-coloured concrete whenever possible.
Early signs: heavy panting, excessive drooling, bright red gums. If you see vomiting, stumbling, or confusion, start cooling them with cool (not ice) water and get to an emergency vet immediately.
Call 911 for immediate danger. You can also report animal distress to the Ontario Animal Protection Call Centre at 1-833-9-ANIMAL. Under the PAWS Act, police can legally break into the car.
Related: 24/7 emergency vets · blue-green algae guide · dog-friendly beaches · off-leash parks · winter safety
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