why are my car windows fogging up on the outside

Exterior fog forms when warm, humid air hits a windscreen that’s been cooled by air-con or a chilly morning, so moisture condenses on the outside.

It’s normal, if annoying—especially after running the A/C then stepping into misty air.

Use the wipers immediately, then switch to the windscreen demist with warmer air to nudge the glass above the dew point; you can leave A/C on to keep the cabin dry.

Avoid recirculate, crack a window, and aim vents at the screen rather than your knees.

If it’s persistent, clean the glass properly; a hydrophobic coating helps the droplets leg it off the screen.

Rear fog? Hit the heated demister and let electricity do the heavy lifting.