How to Stop Your Windscreen Fogging Up in the Rain

A fogged-up windscreen is dangerous. When you can't see, you can't react. Here's exactly why your windows fog up and how to clear them fast.

Why Does Your Windscreen Fog Up?

Condensation happens when warm, moist air inside the car hits the cold glass. Wet clothes, breathing, and damp floor mats all pump moisture into the cabin. When it hits the cold windscreen, it turns into water droplets—fog.

1. Turn On the Air Conditioning

Don't just blast the heat. Your AC system removes moisture from the air. Turn on the AC, crank up the heat, and point it at the windscreen. Turn off the recirculation button—you want fresh, dry air from outside, not the damp air trapped in the cabin.

2. Keep Your Windows Spotlessly Clean

Dirt and oil give moisture something to stick to. Clean glass fogs up far less than dirty glass. Clean the inside of your windscreen with a dedicated automotive glass cleaner and a fresh microfiber cloth. Skip household glass cleaners—ammonia damages window tints and dries out rubber seals.

3. Apply an Anti-Fog Treatment

Anti-fog liquids leave a microscopic film that stops water from beading up. Apply the liquid to a cloth, wipe the inside of the glass, and buff off the residue. One application lasts for weeks.

4. Remove Damp Items from the Cabin

Wet umbrellas, soaked jackets, and damp gym bags release moisture as they dry. Get them out of the car. If you have to keep a wet umbrella, throw it in the boot or seal it in a plastic bag.

5. Use a Car Dehumidifier

If you're dealing with constant fog, put a reusable dehumidifier bag on your dashboard. These silica gel bags pull moisture out of the air while you're parked. When they fill up, microwave them to dry them out and use them again.

6. Check for Leaks

If the glass still fogs up, you've got water getting in. Check your carpets for damp patches. Inspect the rubber seals around doors and sunroofs. A blocked pollen filter will also trap moisture inside the dash—swap it out at your next service.