Home
Weather London
WeatherRadar
RainfallRadar
TemperatureRadar
WindRadar
LightningRadar
Weather News
Editor's Pick
Discover the app
Weather widget
Contact us
Apps
Career
    Home / Editor's Pick /

    Frosty mornings: When to scrape your car

12:00
14 January 2024

Frosty mornings
When to scrape your car

Hoar frost being easily scraped off a car windscreen.
Hoar frost being easily scraped off a car windscreen.

Temperatures plummet in the coming days, and we all know that dreaded feeling of needing to defrost your car in the morning. But we have some tips to help you deal with it!

There are two main reasons that your car might need scraping when it's cold out, and that's because of a hoar frost, or frozen dew.

Hoar frost

Simply put, this is just what we usually call frost. It is the physical ice crystals that you can see on a sub-zero object or surface that has come into contact with moist air, as seen in the image above.

When the surface temperature falls below zero, and then below the dew point, the water vapour turns directly into ice as it cools and condenses on that surface.

Check out our video explainer on frost formation.

It's a white-ish sort of colour, and when you can just use the good old-fashioned windscreen scraper to easily get it off, that's definitely a hoar frost.

Frozen dew

Frozen dew on the other hand, will likely take you longer to get off your windscreen. It's a thin coating of glaze ice, and is what we are more familiar with, as black ice.

It forms in the same way as regular dew, but in a sub-zero environment. So, the surface temperature falls below the dew point first, allowing dew to form, and then falls below freezing. So the existing dew on the surface freezes over, and is awfully difficult to scrape off.

Sometimes you can have a layer of frost covering a layer of frozen dew beneath, which then just creates double the work!

It's often in this case that people are tempted to bring out their kitchen kettles. Whilst modern wind shields are strong, they can still crack, and the seals can deteriorate faster when subject to rapid temperature changes, so avoid this!

Instead, we suggest a de-icer spray, or a pre-ice spray. Alternatively, you can mix up a concoction of three parts vinegar and one part water, which should keep your screens frost-free by morning. Covers can also do the trick.

But how do you know when to do all of this? Well, just be sure to keep an eye on the TemperatureRadar and our top weather tips to know when a frost is likely.

Ice pancakes form in Denmarkread more
Weather & Radar editorial team
More on the topic
Severe weather hits Mallorca and Italy. Severe thunderstorms. . . Thursday, 10 September 2026
Numerous thunderstorms are sweeping across La Palma. The many lightning symbols on the radar and lightning map show that there is heavy lightning activity across large parts of the island. The thunderstorms are striking particularly in the island’s interior and in the south. On the right, you can see the aftermath: a large fallen tree has buried a car beneath it. Emergency services are clearing up the damage. So, along with the thunderstorms, not only heavy rain but also gusts of wind can become a problem.
Thursday, 10 September 2026

Severe thunderstorms

Severe weather hits Mallorca and Italy
Huge low-pressure system off Iceland. Impacting the UK & Ireland. . . Wednesday, 16 September 2026
WeatherRadar showing a large low-pressure system over the North Atlantic between Greenland and Iceland.
Wednesday, 16 September 2026

Impacting the UK & Ireland

Huge low-pressure system off Iceland
Severe weather in southern Europe. Thunderstorms & heavy rain. . . Wednesday, 9 September 2026
On the left, dark storm clouds over a coastline. On the right, a weather map shows thunderstorms over the western Mediterranean, with warning symbols for tornadoes, storms and hail.
Wednesday, 9 September 2026

Thunderstorms & heavy rain

Severe weather in southern Europe
All weather news
This might also interest you
A frozen start to the weekend. Icy conditions. . . Friday, 13 February 2026
UK temperature map dated 14.02 showing widespread subzero values in blue shading, with readings such as −4 in Glasgow, −3 in Dublin, and −2 in London, alongside a blue thermometer icon.
Friday, 13 February 2026

Icy conditions

A frozen start to the weekend
Seasonal warmth between spring thunder. Your weather - Your shots. . . Sunday, 19 April 2026
Split image showing coastal sunset with layered lenticular clouds over rooftops and palm trees on the left, and a green valley with river and hills under soft daylight on the right.
Sunday, 19 April 2026

Your weather - Your shots

Seasonal warmth between spring thunder
A stormy week in the skies above. Your weather - Your shots. . . Sunday, 30 August 2026
Split image showing lightning branching beneath dark storm clouds above rooftops on the left and an orange-pink sunset over a calm sea on the right.
Sunday, 30 August 2026

Your weather - Your shots

A stormy week in the skies above
All articles
Weather & Radar

Weather & Radar is also available on

Google Play StoreApp Store

Company

Contact us Privacy Policy Legal info Accessibility statement

Services

Uploader

Socials

facebooktwittertikToklinkList