What to Do When the Car Windows Fog Up in the Rain and Visibility Is Poor?
3 Answers
Here are solutions for foggy car windows: 1. Open the windows for ventilation: Opening the windows can balance the pressure and temperature difference between the inside and outside of the car, naturally eliminating window fog. After opening the windows, wiping them with hands or paper tools makes it less likely for fog to form again; 2. Turn on the car's air conditioning: Using the car's air conditioning can also achieve the effect of balancing the temperature difference. Simply adjust the temperature to be close to the outside temperature; 3. Use anti-fog spray: Anti-fog spray is a surfactant with hydrophilic ends, allowing it to quickly bond with water molecules in the air on the glass surface and rapidly spread into a thin film, preventing the formation of water droplets and thus avoiding fog. The advantage of anti-fog spray is that it can effectively and significantly prevent moisture from appearing during rainy days and in cold autumn and winter weather. Due to its surfactant properties, it can also make the glass surface cleaner.
I've encountered the issue of foggy windows impairing visibility in rainy weather many times. I remember being completely clueless about what to do when I first started driving. Actually, fog forms due to the temperature difference between the inside and outside of the car, combined with high humidity from rainwater. A simple solution is to immediately turn on the air conditioning, set it to defog mode, and direct the airflow toward the windshield—both cold and warm air work. I've tried this, and it takes just a few seconds to see results. Crack the windows slightly for ventilation, but not too much to avoid rainwater getting inside. If the rain is too heavy, pull over to a safe spot and wait a moment before continuing. Safety comes first—don't risk driving with poor visibility just to save time, as it can easily lead to accidents. It's also a good idea to regularly clean your car windows to prevent dust from worsening fogging issues.
Having driven for over a decade, dealing with rain and fog obstructing visibility is a common occurrence. The most effective method is to turn on the defogger button right after starting the car, combined with the recirculation mode to minimize external moisture intrusion. Sometimes, I carry an anti-fog spray to apply on the glass, which provides good preventive results; or I gently wipe the side mirror area with soapy water—simple and cost-effective. On rainy roads, staying focused is crucial—slow down when fog appears and handle it steadily. Don't rely solely on wipers; the key is the humidity difference inside and outside. Keeping the car's temperature and humidity under control won't make things too bad. Regularly checking the air conditioning system is also a piece of practical advice to avoid functional failures causing delays.
