Illinois Heatwave: Do Windshield Sunshades Really Work Or Not?

As we launch into a week full of high temperatures and heat advisories, most of us are looking for ways to not only keep ourselves cool, but also ideas for keeping our vehicles cooler in the extreme heat.

We see them everywhere this time of year, those shiny accordion-looking sunshields propped up in windshields across parking lots, grocery stores, and ballfields. But with a major Northern Illinois heatwave hitting and heat index values expected to climb into the 105–115 range, it’s fair to ask if car sunshields actually work, or are we just convincing ourselves we’ve done something helpful?

The short answer is yes, they do work, but with some important limits.

batuhan toker

The Main Job Of Sunshields Is...Um...Well...To Shield Things From The Sun

That matters more than people realize. Without a shield, sunlight hits the dashboard and seats, which then absorb and re-radiate heat throughout the car. A reflective sunshade interrupts that process.

Studies and auto experts consistently show that shaded vehicles can have significantly lower dashboard and steering wheel temperatures compared to unshaded ones, sometimes by 15 to 25 degrees or more depending on conditions.

That said, don’t expect a miracle.

A sunshield does not “cool” your car in the traditional sense, and it won’t stop the interior from getting hot during a long parking stretch in full sun. On a 95-degree day, your parked car will still turn into an oven, it just won’t become quite as extreme as it would without any protection.

olegback

It's Not Just The Heat (and no, I'm not going to say it's the humidity)

There are also practical benefits beyond comfort. Sunshields help reduce UV damage, which can crack dashboards, fade upholstery, and age interior plastics faster. That’s a big deal over time, especially for newer vehicles with more sensitive materials.

Still, they aren’t perfect. They take a little effort to set up, can be awkward in tight parking spaces, and don’t help much if your car is already in the shade or only parked briefly.

But for Northern Illinois summers, especially stretches like the one we’re heading into, they’re one of the simplest, cheapest tools available for taking the edge off a brutally hot vehicle.

As noted by Southern Living and Popular Mechanics, they’re not magic, but they’re far from useless either.