What to Do When Car Windows Fog Up in Rainy Weather?

[SanNoah]

The first method is to use the air conditioner to blow on the windows, which can lower the interior temperature. The second method is to use hot air. Close all windows and blast hot air, aiming to reduce the humidity inside the car, which can also minimize fogging.

[RebeccaRose]

I've been driving a taxi for twenty years, so I'm quite experienced when it comes to defogging on rainy days. Before getting in the car, wipe the windows with a cloth. When humidity is high, immediately turn on the cold air and direct it at the windshield. Remember to press the AC button—it uses a bit more fuel, but it defogs twice as fast. If the outside of the rearview mirror fogs up, simply roll the window down and back up; the temperature difference will clear the fog. Experienced drivers start the car five minutes early to let the air conditioning reduce the interior humidity before setting off, which minimizes fogging while driving. Don’t believe the online tips about rubbing soap—it just smears when the wipers swipe. The air conditioning is the most reliable method.