What to Do When the Front Windshield Fogs Up on Rainy Days?

[SanCali]

Here's what you can do when the front windshield fogs up on rainy days: Turn on the heater directly: Increase the fan speed slightly, and the dry, warm air will evaporate the water molecules in the car's interior air, preventing fogging on the windshield. However, this method has a drawback: when frost starts forming on the windshield and the heater is turned on, the water temperature rises. Since water molecules cannot be removed in time, the fog on the glass often increases when the heater is activated. But don't worry—once the overall temperature rises, no fog will form. If it's not raining heavily, you can simply open the windows for a few seconds to clear the fog: The principle is that lowering the interior temperature makes it harder for moisture to condense. Generally, this method works better in winter because the air is drier, and opening the windows can help remove moisture from the car. However, on rainy days when the outside air is more humid, it takes longer to achieve the same effect. You can also turn on the car's defroster directly: This is the simplest way to remove fog. The principle involves blowing dry, cold air from the car's interior onto the front windshield, equalizing the temperature inside and outside the glass and creating a dry air barrier. This prevents condensation of humid air inside the car and stops fog from forming.