How to de-ice a car windscreen safely
On frosty mornings you must clear all your windows before driving. Here's the quick, legal way to do it without cracking the glass or risking your car.
- Time
- 10 minutes
- Difficulty
- Easy
- Cost
- Low cost
- Steps
- 6
- Checked
What you’ll need
- Ice scraper Search Amazon for car ice scraper
- De-icer spray Search Amazon for car de-icer spray
- Soft brush for snow Search Amazon for car snow brush
- Microfibre cloth for inside the glass
- Windscreen cover (optional, for the night before) Search Amazon for windscreen frost cover
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Safety first
- Never pour boiling or hot water on a frozen windscreen. The sudden temperature change can crack the glass, and the water can refreeze on the screen or the ground.
- Don't use a credit card, CD or metal object to scrape: they can scratch the glass.
- Driving without a clear view breaks the Highway Code (rule 229) and can lead to a fine and penalty points.
Step by step
-
Step 1: Allow enough time
Leave around 10 extra minutes on frosty mornings so you aren't tempted to set off peering through a small gap.
Next: step 2 -
Step 2: Start the engine and turn on the heater
Start the engine, set the heater to hot and direct it at the windscreen, and switch on the heated rear window (and heated windscreen or mirrors if you have them). Air conditioning helps dry the air and clear misting inside. Stay with the car: the Highway Code says you must not leave a vehicle's engine running unnecessarily while it's stationary on a public road, and an unattended running car is an easy target for thieves.
Next: step 3 -
Step 3: Spray and scrape
Spray de-icer on the glass, then use a plastic scraper to clear every window, not just a porthole in the windscreen. Scrape the side windows and rear window too.
Next: step 4 -
Step 4: Clear mirrors, lights and number plates
The Highway Code says you must keep your lights clean and number plates clear and readable. Clear the door mirrors as well.
Next: step 5 -
Step 5: Brush off snow
Brush snow off the roof, bonnet and boot as well as the glass. Snow on the roof can slide onto your windscreen when you brake, or blow onto vehicles behind you.
Next: step 6 -
Step 6: Demist the inside
Wipe any remaining condensation from the inside of the glass with a clean microfibre cloth, and make sure the windows are fully clear before you drive off.
Tips
- A windscreen cover or even an old towel held in place by the wipers the night before saves scraping.
- Clean the inside of your windscreen regularly. Dirty glass mists up more easily.
- Make sure your screenwash has an additive suitable for freezing temperatures.
- Free the wipers before switching them on. If they're frozen to the glass, the motor or blades can be damaged.
When to call a professional
If you notice a chip or crack, get it looked at by a windscreen repair company. Cold weather and heater blowers can make cracks spread, and damage in the driver's line of sight can be an MOT failure.
Questions people ask
Is it illegal to drive with a frosty windscreen?
Yes. Highway Code rule 229 says you must be able to see, so all snow and ice must be cleared from all your windows, and lights and number plates must be clean and readable.
Can I leave my car running to defrost?
Highway Code rule 123 says you must not leave a vehicle's engine running unnecessarily while stationary on a public road. Stay with the car while it warms up, and never leave it running unattended.
Is lukewarm water OK?
It's best avoided. Even warm water risks thermal shock to cold glass and can refreeze. Use de-icer and a scraper.
Sources
Checked 9 October 2026. We wrote this guide in our own words, using:
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Printed from howtoguides.uk/guides/how-to-de-ice-a-car-windscreen/ · Checked 9 October 2026 · General information only. For gas, electrics, structural work, medical, legal or money decisions, use a qualified professional.