how hot can a car get in the sun

[TeaganLee]

A car parked in the sun on a hot day can reach internal temperatures of 130°F to 200°F (54°C to 93°C) within an hour. The exact temperature depends on the outside air temperature, sunlight intensity, and the color of the car's interior and exterior. This rapid heating poses significant health risks and can damage belongings left inside.

The primary reason for this extreme heat is the greenhouse effect. Sunlight passes through the windows as short-wave radiation, which is absorbed by the dashboard, seats, and other surfaces. These surfaces then re-radiate the energy as long-wave heat, which cannot escape through the glass as easily, trapping the heat inside the cabin.

The rate of temperature increase is most dramatic within the first 30 minutes. On a sunny day with an ambient temperature of 85°F (29°C), the inside of a car can become a life-threatening 119°F (48°C) in just 20 minutes.

Elapsed Time (Minutes)	Approximate Interior Temperature (Outside Air Temp: 85°F / 29°C)
0	85°F (29°C)
10	100°F (38°C)
20	119°F (48°C)
30	130°F (54°C)
60	143°F (62°C)

Darker interior colors, like black leather, absorb significantly more heat than light-colored cloth. A cracked window has a minimal effect on slowing the heating process. It is crucial to never leave children or pets unattended in a vehicle, as their bodies heat up three to five times faster than an adult's. High temperatures can also damage electronics, medications, and plastic items.

[LeJudah]

As a parent, this is my biggest fear. I’ve felt that blast of oven-like heat when opening a car door I just left for ten minutes. It’s not just uncomfortable; it’s deadly for a child. Their bodies can’t regulate temperature like ours. I never, ever leave my kids in the car, not even for a "quick" errand. The temperature soars way too fast, and it’s a risk I’m never willing to take. It’s just not worth it.

[SanRemington]

Living in Arizona, you learn this fast. Your steering wheel can literally burn your hands. I keep a sunshade in my windshield year-round. It doesn’t stop the heat completely, but it helps a ton by blocking the sun from directly hitting the dash. I also try to park in the shade of a building or a tree whenever possible. Tinted windows are another good investment. The key is to block as much direct sunlight as you can before it even hits the interior surfaces.

[VanAngela]

It’s a straightforward physics problem. The car’s cabin acts like a solar radiator. Short-wave solar radiation passes through the glass and is absorbed by the interior materials. These materials then emit long-wave infrared radiation, which is trapped by the glass—this is the greenhouse effect. The heat continues to build until the energy entering the cabin equals the energy escaping, which can be at a dangerously high equilibrium. The material's thermal mass and color directly influence the absorption rate.

[Morris]

I learned this lesson the hard way when a plastic water bottle I left in my cupholder warped and melted. It was a sunny, 90-degree day, and I was only in the store for about half an hour. When I got back, the car was unbearable to sit in. Now, I’m meticulous about what I leave behind. No electronics, no cans of soda, and definitely no medication. It’s surprising how quickly an ordinary day can turn your car into an oven capable of damaging your stuff.