What to Do When the Front Window Fogs Up on Rainy Days?
3 Answers
Methods to remove fog from the front window on rainy days: 1. Air conditioning cold air; 2. Air conditioning hot air or heating; 3. Defogging agent; 4. Rear window heating wire defogging; 5. Detergent-type anti-fog. When fog is noticed on the windshield, the quickest and most efficient method is to first adjust the air conditioning vent to the front windshield, turn on the air conditioning cooling function, and activate the external circulation. Using the maximum fan speed, it usually takes only about ten seconds to quickly blow away the fog on the glass. If you want to completely eliminate fog inside the car, you should choose to use the air conditioning hot air to blow the windshield. Similarly, start with the external circulation, select the hot air and front windshield vent, wait for about 5 minutes, then switch to internal circulation or simply turn it off.
Foggy front windows on rainy days are particularly annoying, something I've encountered many times over years of driving. The main reason is that rain increases air humidity, and the temperature difference between the inside and outside of the car causes exhaled air to condense on the cold glass, creating fog that obstructs visibility—a dangerous situation. I usually turn on the air conditioning immediately, set the fan to maximum, and switch to external air circulation to dehumidify and improve airflow. If the temperature is low, I might add some warm air but keep the AC on to maintain a drying effect. Wiping the glass with a clean cloth before driving helps prevent fogging by removing any grease residue. Once, I was in a hurry and forgot to deal with it, nearly causing an accident. Since then, I always keep a bottle of anti-fog spray handy, regularly applying it to keep the glass clean. Remember, when dealing with fog, stay focused on driving—don’t get distracted by wiping—and prioritize safety. This way, driving in the rain becomes much more reassuring.
When I first started learning to drive, I found the foggy windows on rainy days quite troublesome—the glass would fog up as soon as I got in the car. The simplest solution I discovered is to press the defog button (the one with the small arrow icon) right after starting the car, turn the fan to maximum to blow air at the windshield, and turn on the air conditioning for better dehumidification. Opening the side windows slightly for ventilation can also help quickly disperse the moisture, but don’t open them too wide to avoid letting rain in. Avoid wiping the glass with a cloth while driving—it’s too dangerous. I keep a defogging spray in my car and use it before heading out on rainy days to prevent fogging in advance, saving me from scrambling on the road. Weather forecast apps on my phone provide humidity alerts, and I make it a habit to check them and prepare more on high-humidity days. These small habits have helped me a lot, making it easier for beginners to handle such situations.
