Cool down a hot car interior faster with this guide.

How long should it take to cool down a hot car interior?

Hot car? Beat the heat by learning how to cool down a hot car interior faster.

We’ve all been there: it’s been a long day. You’re exhausted and ready to head home. You throw open our car door, and are met immediately by a wall of ferocious, caged heat — as if the 112°F outside the car wasn’t bad enough!  So, how do we subdue this foe?  How do we restore habitable temperatures as quickly as possible to the interior of a car that has been baking in the heat all day?

How long should it take to cool down a hot car interior after it’s been sitting in the sun all day?

Well, the answer depends on how hot the car is to start with, what condition is your car’s air conditioning system is in and what process you use to cool it down after you start the car.

If your car is parked under the sun all day, the temperatures are most likely well over a 120° (sometimes climbing as high as 135°) Fahrenheit, so we’re here to show you how to cool down a hot car and go from sweat-box to comfortable commute as quickly as possible.

Step 1: Door-Fanning

For this step, we’re gonna use some good, old-fashioned Mr. Wizard science, and work our door like a giant, make-shift fan.  This is a two-part process:

a. The very first thing you want to do, is roll down the front, passenger-side window.  If you can do this without getting all the way into your vehicle, that would be ideal.  But, if you have to get in for any reason, you can rest easy knowing that as soon as you get that window down, you can hop right back out.

b. Once that window is down (and the door is shut, if you had to open it), return to the driver’s side (or jump back out, if you had to get in to roll the window down), and begin fanning your car door in and out about 8-10 times.

This will force a lot of the hot air that’s been bottled up in your call day out, while sucking cooler air from outside in – because (believe it or not) that 100° outside-air is significantly cooler than the boiler room inside your car.  Now, your AC will have a lot less work to do, to get you back to comfortable.

Step 2: Get the Car Moving

Now that we’ve given the AC a better jumping-off point, we’re going to prime it so we can maximize its efficiency. Go ahead and roll your front passenger-side window up, settle in behind the wheel, and start the car.  The reason you want to begin driving, as opposed to just cranking the AC and letting it run while your car idles, is because the air conditioning requires air to be moving over the condenser (located just in front of of behind the radiator at the front of your engine bay) before it can start conditioning it. Driving your car is going to force the necessary air movement more quickly than the radiator fans alone will do, which will prepare your AC for maximum cooling.

Step 3: Blast that AC

After driving around for a bit, and forcing all that air over your condenser, it’s now time to bring in the heavy artillery. Crank the AC dial to “Max” (or whatever your car denotes as the ‘Highest Setting Possible’), which will set your system into recirculation mode. A few quick notes:

  • When you first turn on your AC, the air that’s going to be coming out of those vents will likely still be hot.  That’s to be expected, so do not be alarmed.  Just allow the AC to run for a bit, and you’ll notice colder air in no time.
  • Be sure that, when you first turn on your AC, the setting to recirculate the air inside your car is not selected.  You want to be bringing in the air from outside, as it’s likely cooler than the air inside, and easier for your AC to work with. This way, you’re bringing in cool air and dumping the sweltering cabin air outside where it belongs. Once the temperature inside is cooler than the temperature outside, change to the recirculation setting, for the same reason.  This way you’re always cooling down the coolest air you have available to you, allowing your AC to work as quickly and efficiently as possible.

Then, with the AC blasting and the car moving: crack open all your windows, sunroofs, moonroofs, etc.  Don’t open them all the way up (we don’t want any of this refreshing cool air escaping), just enough to help flush out some of the remaining hot air, that we’re replacing with the cooled-down air from outside.  After a minute or two – once the car has cooled down to a comfortable level – shut all the windows, sunroofs, moonroofs, etc. to seal in the cool air

That’s it!

The whole process should take about 5-10 minutes. Remember, even though the vents are blowing cold air, the car’s interior may still be radiating the absorbed heat. It could take an additional 10 minutes to absorb and exchange the heat from the seats and dash.

Preventative Measures You Can Take

Sometimes the best offense is a good defense. Consider taking one or more of the following measures to keep your car’s interior from getting quite so hot in the first place.


Using a sunshade can dramatically decrease the amount of heat build up in your car while it sits.  Just put one in whichever window is facing the sun. If you’re using it to block sun coming in the windshield, unfold it and hold it in place against the windshield, then lower your driver and passenger visors to keep it in place. They also make sunshades with suction cups, if you prefer. The kind that go in your side windows will most likely have them, as well.

Cover Your Seats

As mentioned above, your seats can absorb a lot of heat, which will continue to radiate out, prolonging the time it takes to cool down the inside of your car.  The darker the seat color, the more heat it will absorb.  So, if your car’s seats are black, or brown, or maroon, or anything similar, you may want to consider purchasing some seat covers that are white, or tan, or anything lighter than what you currently have, really.

Find Shade

If you’re not parking your car in a parking garage, try and locate some shade to park under; a bushy tree, or a neighboring building are prime sources.  Even if you have to park a little further away, a slightly longer walk in the heat can often be a worth the cooler interior car temperature.


This is the easiest and cheapest (in that it’s free) option.  Simply crack your windows a bit, to prevent the air from getting trapped inside your car, and helping to maintain an internal temperature that’s closer to the outside temperature.  There are two potential drawbacks to this option, however:

  1. A cracked window could be an inviting opportunity for theft, so it’s important to be mindful of this, and not crack your windows too far, or in areas you aren’t familiar with/can’t easily monitor.
  2. Rain.  As you can probably imagine, a poorly-timed rainstorm paired with cracked windows is a sure-fire recipe for wet seats and unpleasant smells, among other things.  If you’re going to crack your windows, be sure to read up on the forecast for the day, and be sure you’re in a position to get back to your car in the even Mother Nature throws you a curveball.

Now you’re armed with the best weapons to not only battle the heat, but to quickly banish it and cool down a hot car the fast way – and even prevent it from becoming such a monster to begin with. This all hinges, though, on one key component: the condition of you car’s AC System. Autoscope recommends that you have your A/C system checked annually, so you can keep it operating at peak performance. If you find that the AC system in your European car isn’t working as well as it once did, give us a call set up an appointment online today to have one of our qualified European auto repair technicians quickly diagnose and repair any AC problems you might be having.

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