15/06/2026
If you’re getting ready to travel and your windscreen is foggy, here’s the fastest way to clear it:
• Turn your demister on.
• Turn your air conditioning to full strength at its hottest temperature.
• Turn circulating air off.
• Open the windows by a few centimetres, even if only for 20–30 seconds.
You should turn circulating air off because cold air from outside will clear fog faster than recirculated air in your car, which is already hot and has already absorbed some condensation.
In other words, cold and dry air is better than warm and moist air.
The circulating air symbol looks like a car with a U-shaped arrow in it – turn it off.
Opening the windows just a little will help clear the humid air inside, replacing it with colder air from outside. This speeds up the process a bit but it's a nice-to-have – sometimes it'll be raining, or just really cold outside.
If you’re not sure what your demister looks like, its symbol looks like three arrows pointing up at a curved rectangle. In most modern vehicles this symbol will be on a button you can turn on or off, but in older vehicles it may be a setting you need to select using a dial.
We've all seen people driving around with a foggy windscreen, and with foggy windows too. It's illegal to drive with a foggy windscreen (under section 8.8 of the Land Transport (Road User) Rule), so clear your windscreen and keep it clear as you’re travelling.
When the weather is bad, always check our pages to see if state highways are affected before you travel. Follow us if you aren’t already. You can find more information in this post: https://www.facebook.com/share/p/1HJqwn4Sxa/
