Click4Assistance UK Live Chat Software

How to properly demist your windscreen


When the weather gets wet and cold, a fogged-up car windscreen can be a major hassle. It can add time to your commute, leave your car damp or mouldy, and waste fuel. More than this though, it is dangerous for your windscreen to be misty or fogged up. The highway code states that “windscreens and windows MUST be kept clean and free from obstructions to vision”[1], this includes condensation.

This means it’s important for you to learn how to demist your windscreen easily with this step-by-step guide for a quick and safe start to your journey.

Whether you have a heater, air conditioning, or neither, here are some simple steps to properly demist your windscreen.

Why do windshields fog up?

Ready for a science lesson? These are some reasons that you might need to demist your windscreen:

  • Temperature in the car is warmer than outside: Warm air holds more moisture than cold air. When warm air meets a cold windshield, water molecules turn into gas, causing fog.
  • How condensation is made: Warm, moist air hitting a cooler windshield will result in condensation. This often occurs in the morning or when using the car air conditioner on humid days.
  • There are lots of people in the car: More people in the car means more breathing, leading to increased humidity. The water in the air you breathe out settles on the inside of the car’s windscreen.

In high humidity, if the temperature drops, water seeks an outlet, leading to foggy conditions on cool mornings. Understanding these factors helps in addressing windshield fog effectively.

Can I use air conditioning to demist my windscreen:

Man hand set the temperature of air conditioner in the car. Driver turning on car climate control system. travel by car. Close up view with selective focus.
Man hand set the temperature of air conditioner in the car. Driver turning on car climate control system. travel by car. Close up view with selective focus.

Your air conditioning (AC) can be used to demist your windows. You can do this by following these quick steps:

  1. Turn on engine: Begin by turning on your engine and allowing it to warm up.
  2. Turn off the recirculation button: Fresh air helps to reduce humidity.
  3. Switch on AC: This helps reduce the moisture in the air, reducing the humidity within the vehicle.
  4. Adjust temperature and Fan: Select a warm temperature and high fan speed.
  5. Direct air: Guide the airflow towards the windows.
  6. Wait: After a few minutes the mist on your windows should dissipate.

If you’re not sure about the air conditioning buttons in your car – check out our blog ‘what the air conditioning buttons in your car mean.’

How to use the heater for demisting:

Woman regulates heating in her car. Modern car interior

If you don’t have air conditioning, you can use your car’s heater to demist windows. To do this you should:

  1. Turn on the engine.
  2. Turn on your heater: It may take a few minutes to produce any hot air, especially in colder months.
  3. Select a low temperature: To start with, select a low temperature and slowly increase to hot air. Starting with hot air may increase humidity and make the misty windscreen worse.
  4. Move your fans: Direct the fans/vents towards the windows and windscreen and select a high-speed setting.
  5. Open windows slightly: Opening windows a tiny bit will help exchange the humid interior air with drier air from outside.
  6. Wait: After a few minutes, the mist on your windows should disappear.

How to demist your windscreen without AC or a heater:

Woman in a red checked shirt wiping the windshield of the car from the inside of a white vehicle.

It can be difficult trying to drive without a functioning air conditioning or heater, especially in the winter months where your windows are misted over. However, you can still demist your windows effectively without them.

  • Open your windows: While not ideal in the colder months, allowing outside air into your vehicle can help reduces the humidity that causes misting.
  • Dry with a microfibre cloth: If you’d rather stay warm you could use a microfibre cloth to wipe the mist from inside of your windows before driving. Remember, dry the cloth before your next journey to avoid a smeary window.

Windscreen life hacks

If all else fails and you really want to stop the misting up in the first place, keeping your windscreen clean will help it stop misting it up in the first place.

There’s a tip you can steal from Ice Hockey players and clean your windscreen with shaving foam. the detergent in the shaving foam can prevent the water from beading on your car windows and windscreen. Here’s how to do it:

  1. Use a clean towel and spread a tennis ball size of foam over your windscreen, spreading it over the whole area.
  2. Use a different clean towel to wipe it off completely.
  3. This will need repeating, as the effect doesn’t last permanently but should help create a barrier.


It’s important to remember to never leave your vehicle unattended while demisting/defrosting your windscreen. Staffordshire Police issued a warning in November 2023 after a driver’s vehicle was stolen from their drive as they left their keys in the ignition while defrosting their windscreen. You should never leave your vehicle unattended with the keys inside. Your insurance company may not pay out if your vehicle is stolen in this way [2].

You can make a claim on your GoSkippy policy here.

So, next time your windscreen fogs up, follow these tips for a clear view and a smoother drive. Safe travels!

First things first though, make sure you’re insured to drive the vehicle before tackling the task of demisting your windscreen—it’s the crucial first step before hitting the road.

Get a quote with GoSkippy today!

[1] The Highway Code – Annex 6. Vehicle maintenance, safety and security – Guidance – GOV.UK (

[2] Warning issued following theft of unattended vehicle while defrosting | Staffordshire Police