What is the temperature inside a car parked in the sun?

From a safety perspective, the temperature inside a sunlit car can become lethal within minutes. Studies show that even on a 22°C day, interior temperatures can reach 47°C in an hour. Children and pets are particularly vulnerable, as their bodies overheat faster. Always check the back seat before leaving, and never assume "just a few minutes" is safe.

Tests have shown that when a car is parked outdoors at 40°C and exposed to prolonged sunlight, the interior temperature can exceed 70°C, reaching up to 90°C. Most car interiors are black, which absorbs heat more efficiently, and the enclosed environment causes temperatures to rise rapidly under prolonged exposure, turning the car into an oven.

Long-term exposure to high temperatures can also damage car components. For example, it accelerates paint aging and fading, shortening the paint's lifespan; it speeds up the deterioration of rubber seals, causing cracks; it hastens tire aging, leading to deformation, cracking, and reduced tire lifespan, while also potentially increasing tire pressure and causing blowouts. Since most interior materials are plastic or leather, prolonged exposure can also release harmful substances like formaldehyde.

How to quickly cool down a hot car:

1. Use sunshade tools: Purchase car-specific sun protection gear, such as a sunshade, and place it on the windshield to reduce UV exposure. This not only lowers interior temperatures but also prevents dashboard aging and leather seat cracking.
2. Use the air conditioner: Before entering the car, open all four windows for ventilation. Then, set the AC to the lowest temperature, turn on recirculation mode, direct airflow toward the footwells, and set the fan to maximum to expel hot air. Once the interior matches the outside temperature, close the windows, switch to recirculation, and adjust to a comfortable temperature.
3. Use a cooling spray: Some commercially available sprays contain dry ice. Shake the can lightly and spray inside the car to rapidly lower the temperature.
4. Use alcohol: Since alcohol evaporates quickly, it absorbs and carries away heat, providing rapid cooling. Spraying 70% alcohol inside the car can quickly reduce the temperature. Be cautious with the concentration, as alcohol is highly flammable.

The temperature inside a car parked in direct sunlight can rise rapidly, reaching dangerous levels. On a typical summer day with an outside temperature of 21°C, the interior can exceed 40°C within an hour. If the outside temperature is closer to 30°C, the car’s interior can surge to 50°C or higher. Darker-coloured cars absorb more heat, accelerating this effect.

Several factors influence this:

1. Sun intensity – Direct sunlight increases heat buildup.
2. Duration – The longer the car is parked, the hotter it gets.
3. Ventilation – Closed windows trap heat, while cracked windows only slightly reduce temperatures.
4. Interior materials – Leather and dark upholstery absorb more heat than lighter fabrics.

Leaving children, pets, or perishables in a parked car is extremely hazardous. Even on mild days, temperatures rise quickly. If you must leave items in the car, park in shade, use sunshades, and avoid prolonged exposure. Modern cars with cabin pre-conditioning (like Tesla Model 3) can help mitigate this, but passive heat buildup remains a serious risk.