Why Does the Outside of the Car Window Fog Up at Night?
2 Answers
When the temperature inside the car is higher than the outside, the large temperature difference between the warm interior and cold exterior causes fogging. Here are some solutions: 1. Ventilation to Remove Fog: If the fog is not too heavy, you can slightly open both side windows to allow air circulation. This equalizes the temperature difference on both sides of the windshield, making it difficult for fog to form. Turning on the air conditioner's cold air can quickly eliminate fog. 2. Anti-Fog Spray: The principle of anti-fog spray is simple—spraying it on the windshield forms a protective film that prevents water vapor from condensing. However, this protective film is short-lived and requires frequent reapplication to maintain effectiveness.
Fogging on the outside of the car windows at night is quite common. The main reason is the high external temperature and humidity, which causes water droplets to form when they come into contact with the cold surface of the windows. Imagine this: after dark, the temperature drops, especially if it's raining or the humidity is high. The moisture in the air outside the car condenses into fog when it touches the colder glass. This affects visibility and can be quite dangerous. I recommend immediately turning on the windshield wipers to clear it or activating the car's front defroster to prevent it. Sometimes, if the windows aren't clean or have an oily film, they're more prone to fogging. Regularly wiping them with a specialized cleaning agent can be very helpful. Safe driving is the top priority, so slow down if you encounter this situation. Overall, nighttime fogging is mostly caused by temperature differences and high humidity, and knowing how to deal with it is key.
