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

Severe flooding in the south of France. Roads become rivers. . Weather Videos. Wednesday 21 October 2026
Weather radar shows heavy rainfall over southern France, northern Italy, Corsica and Sardinia. A warning symbol indicates a risk of flooding.
Weather VideosWednesday 21 October 2026

Roads become rivers

Severe flooding in the south of France
Winds grow and rain spreads Wednesday. Prelude to Austen. . . Wednesday 21 October 2026
Split weather map showing strong winds up to 40 mph across southern Britain and blue rain bands over Scotland, Ireland and England, with warning symbols.
Wednesday 21 October 2026

Prelude to Austen

Winds grow and rain spreads Wednesday
Shooting stars from the Orionids peak. Mixed visibility overnight. . . Wednesday 21 October 2026
Split image showing a bright green meteor streaking across a starry night sky beside a UK weather map with rain over Scotland and southern England.
Wednesday 21 October 2026

Mixed visibility overnight

Shooting stars from the Orionids peak
All weather news

This might also interest you

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
Long-term trends need a pinch of salt. 40 °C in July?. . . Tuesday 30 June 2026
Temperature radar of 2022 heatwave where the all-time temperature record in the UK was set. Warning symbol overlain.
Tuesday 30 June 2026

40 °C in July?

Long-term trends need a pinch of salt
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

facebooktwitteryouTubelinkList