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

    Frosty mornings: When to scrape your car

10:30
29 November 2023

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.

We all know that dreaded feeling of needing to get up early to defrost your car in the morning. But we have some tips to help you deal with it!

There are two main reasons that you 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 windshields 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.

Weather & Radar editorial team
More on the topic
A snowy winter in the Andes. Avalanches and storms. . . Tuesday 15 September 2026
Tuesday 15 September 2026

Avalanches and storms

A snowy winter in the Andes
Severe weather in the Mediterranean. Is a medicane on the way?. . . Monday 14 September 2026
A weather map shows a powerful low-pressure system over the Mediterranean, with warning symbols for storms and heavy rain.
Monday 14 September 2026

Is a medicane on the way?

Severe weather in the Mediterranean
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
All weather news
This might also interest you
Bright and warm conditions take hold. Spring-like outlook. . . Thursday 23 April 2026
Split UK map showing warm temperatures up to 21 degrees in orange on the left and clear sunny conditions with temperatures from 12 to 18 degrees on the right, with sun icons across the country.
Thursday 23 April 2026

Spring-like outlook

Bright and warm conditions take hold
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
Flooding, gales, and heavy snow. Storm Chandra. . . Tuesday 27 January 2026
Split image showing aerial flooding in a town with muddy water covering roads on the left, and a rural road on the right blocked by heavy snowfall with vans stopped and a person walking in snow.
Tuesday 27 January 2026

Storm Chandra

Flooding, gales, and heavy snow
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

facebooktwitteryouTubelinkList