5 Ways to Keep Your Car’s Interior Cooler

Temperatures are soaring across the country, turning car interiors into upholstered ovens. Even if your vehicle’s air conditioning is in good working order, that doesn’t change the fact that it’s going to get very hot inside when the engine isn’t running.

Yes, parking in a garage or somewhere else with shade is better than the sun beating down on your seats all day, but when temps reach the 80s, 90s, and certainly, the triple-digits, the interior is going to get hot — even in the shade. Here are a few strategies to help you deal with it.

How hot does it get inside a car?

When it’s hot outside, a car’s interior temperatures can get dangerously high very quickly.

For a 2018 study published in the journal Temperature, the researchers conducted a range of real-world tests, including one where cars were parked in both in the sun and the shade for one hour when the outdoor temperature was 35°C.

After the hour, the average air temperature inside the cars in the sun was 47°C. The average temperatures of various surfaces were even higher, like the dashboards (69°C), the steering wheels (52°C), and the seats (50°C).

Meanwhile, the average air temperature inside the cars parked in the shade during that same period was 38°C. The average temps of various surfaces increased as well, including the dashboards (47°C), the steering wheels (41°C), and the seats (40°C). So yes, it is cooler in the shade, but still extremely hot.

How to keep your car’s interior cooler in the summer

Here are a few methods for cooling down your seats and steering wheel, as well as handling your car’s interior when it’s scorching hot:

1. Use (or make) cool packs for the seats: Basically, these are giant versions of those freezer packs you put in a cooler or lunchbox to keep food chilled. Though they’re usually marketed for children’s car seats, grown-ups deserve cool butts, too. They’re widely available for purchase, or you can make your own DIY version.
2. Stash instant cold packs in the trunk: This isn’t an everyday solution, but for times when you need to cool down your seats, steering wheel, or another part of your interior (or yourself) immediately, activating one of these (the kind you pop open and are often found in first aid kits) can help.
3. Use a pot holder or oven mitt for buckling seatbelts: An option if your seatbelt is too hot to touch. Any rag or towel would work too.
4. Drape a white towel over your steering wheel: Really, most colours would do (we’ll talk about that in a minute); simply having something covering the wheel will help.
5. Use a windshield sun shade: These are more useful for keeping the steering wheel and dashboard cool than the seats or interior air temp, but they do help. Be sure to buy the right shape and size.

Does the colour of a car’s interior make a difference?

Conventional wisdom says that dark-coloured interiors get much hotter than lighter ones, but that’s a bit of an overstatement. Test engineers at Consumer Reports measured the interior temperatures of two cars: One with a light-coloured exterior and light-coloured interior, and the other with a dark exterior and dark interior.

Both cars were parked outside, and started off with an interior temperature of 25°C. After an hour, the temperatures inside both cars had exceeded 37°C, with the darker car being a few degrees hotter.

The CR test engineers concluded that “a light-coloured interior is going to be slightly cooler, but when you’re talking over 37°C inside, it’s really hot either way.”