how hot can a car get in the sun

On a beautiful sunny day, your car can feel like a lifesaver, offering a cool escape from the heat. But when it’s been sitting in a parking lot for a few hours, opening the door can feel like stepping into an oven. The temperature inside a parked vehicle can skyrocket to dangerous levels in a remarkably short amount of time, creating a serious risk for anyone or anything left inside. It’s a common question many drivers have, especially during the summer months: just how hot can a car get in the sun?

The Surprising Answer to How Hot Can a Car Get in the Sun

The numbers are truly startling. On a mild 75-degree Fahrenheit day, the inside of your car can reach a scorching 100 degrees in just 30 minutes. As the outside temperature climbs, so does the interior heat. On a 90-degree day, the cabin temperature can soar to a dangerous 109 degrees in 10 minutes and a life-threatening 124 degrees in 30 minutes. This rapid heating happens because sunlight enters through the windows, and the trapped energy turns the car’s interior into a greenhouse, with surfaces like dashboards and seats absorbing and radiating heat.

Why the Inside Heats Up So Quickly

This intense heat buildup is due to the greenhouse effect. Sunlight passes through the car’s windows as short-wave radiation, which is then absorbed by the seats, dashboard, and other surfaces. These objects then re-radiate the energy as long-wave heat, which cannot easily escape back through the glass. This cycle causes the trapped air temperature to climb rapidly and steadily, regardless of the car’s color, though darker interiors will absorb heat slightly faster.

Protecting Your Car and Your Passengers

The most critical rule is to never leave a child or a pet in a parked car, even for “just a minute.” Cracking the windows open has been shown to have little effect on the rising temperature. To make your car more comfortable upon return, try using a sunshade for your windshield and park in the shade whenever possible. For your own comfort, when you get back to a hot car, open the doors for a minute to let the superheated air out before turning on the air conditioning. This helps your AC work more efficiently.

Being aware of just how quickly a car can heat up is the first step in preventing a tragedy. A few simple habits, like always checking the back seat and planning errands that don’t require leaving anyone in the car, can make all the difference in ensuring everyone stays safe and cool.