How fast does a car heat up in the sun?

A car's interior temperature can rise nearly 20°F in just 10 minutes. On a 70°F day, the inside of a car can reach 89°F in 10 minutes and 104°F in 30 minutes. On a 95°F day, interior temperatures can reach 114°F in 10 minutes and 129°F in 30 minutes.

What temperature is too hot to leave a dog in a car?

There is no safe temperature to leave a pet in a parked car. Even on a mild 70°F (21°C) day, the interior of a car can reach dangerous temperatures within minutes. Pets can suffer heatstroke and die in as little as 15 minutes.

Does cracking the window help keep a car cool for pets?

No. Studies show that cracking the windows has little effect on the interior temperature of a parked car. The greenhouse effect traps heat regardless of slightly open windows.

What are the signs of heatstroke in dogs?

Signs include excessive panting, drooling, rapid heartbeat, dark or red gums and tongue, glazed eyes, vomiting, diarrhea, staggering, collapse, and seizures. Heatstroke can be fatal without immediate treatment.

How long does it take for a car to get hot?

Car Temperature Pet Safety Chart

Within minutes, interior car temperatures can reach deadly levels for pets — even on a mild day. See exactly how fast temperatures rise and what you can do to keep your pets safe.

Originally published 2012 · Updated March 2026

Shared millions of times Free printable PDF Learn signs of heatstroke

Vehicle Temperature Data

How fast interior car temperatures rise based on outside temperature. Data based on studies by the San Francisco State University Department of Geosciences.

Outside Temp	10 minutes	20 minutes	30 minutes	60 minutes

Why Cars Are So Dangerous for Pets

Even well-meaning pet owners underestimate how quickly a car becomes an oven.

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It Only Takes Minutes

On a 75°F day, the inside of a car reaches 94°F in just 10 minutes and 109°F in 30 minutes. Dogs can suffer brain damage or die at body temperatures over 106°F.

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Cracking the Window Doesn't Help

Studies show partially open windows have little to no effect on interior temperature. The greenhouse effect traps solar radiation inside the vehicle regardless.

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Dogs Can't Cool Down Like We Can

Dogs primarily cool themselves through panting, which becomes ineffective in hot, humid, enclosed spaces. They overheat far faster than humans do.

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Even Mild Days Are Dangerous

A "comfortable" 70°F day outside means 104°F inside a parked car within 30 minutes. There is no safe temperature to leave a pet in a parked car.

Signs of Heatstroke in Pets

Heatstroke can progress from mild to fatal in minutes. Know these warning signs.

Excessive panting

Heavy drooling

Rapid heartbeat

Dark or red gums

Glazed eyes

Vomiting

Staggering / weakness

Collapse

Seizures

What to Do If You See a Dog in a Hot Car

Acting quickly can save a life. Here's what experts recommend.

Note the vehicle details — make, model, color, and license plate number.

Try to locate the owner — alert nearby businesses. Have them paged over the intercom if at a store or mall.

Call 911 or local animal control — report the situation. They can respond and legally intervene.

Stay with the animal — monitor its condition. Note the time you found the animal and document with photos.

Know your state's laws — many states have "Good Samaritan" laws that protect people who rescue animals from hot vehicles. Laws vary by state.

Spread the Word — It Could Save a Life

Share this chart with friends, family, and your local veterinary clinic. Print it and post it at your workplace.

Download Free Printable PDF