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
The second warmest May on record. Early heatwave in Europe. . . Wednesday 10 June 2026
Split image showing a European temperature anomaly map with widespread warmer-than-average conditions on the left and a poerson cooling off beside a fountain near the Eiffel Tower during hot weather on the right.
Wednesday 10 June 2026

Early heatwave in Europe

The second warmest May on record
Summer comeback on the horizon. Hot air from Spain. . . Tuesday 9 June 2026
European weather map showing temperatures and weather symbols. A red arrow points from Spain and southern France towards Central Europe, indicating the influx of very warm air. A sun-and-cloud symbol is shown over Germany, indicating pleasant, partly cloudy weather. Maximum temperatures of over 30 degrees are forecast for Spain and Portugal, whilst in Germany, France and the Alpine regions temperatures are mostly between 22 and 25 degrees. The map illustrates a warm south-westerly flow transporting summer air towards Central Europe.
Tuesday 9 June 2026

Hot air from Spain

Summer comeback on the horizon
Tropical storm hits Mexico. Ahead of the World Cup. . . Monday 8 June 2026
A small weather map showing satellite imagery and precipitation over Europe. A red warning triangle with an exclamation mark is displayed in the bottom left-hand corner. The map shows numerous blue, yellow and orange weather symbols indicating active precipitation or areas of thunderstorms. The graphic conveys a general weather or severe weather warning.
Monday 8 June 2026

Ahead of the World Cup

Tropical storm hits Mexico
All weather news
This might also interest you
Storm Chandra makes impact. Severe gales & heavy rain. . . Tuesday 27 January 2026
Split image showing strong winds over the UK on a forecast map and widespread rain and snow on a weather radar map.
Tuesday 27 January 2026

Severe gales & heavy rain

Storm Chandra makes impact
Historic Storm Éowyn arrives. On this day.... . . Saturday 24 January 2026
Split image showing a person in a yellow jacket struggling against strong winds and heavy rain on a street at night on the left, and an Irish wind forecast map on the right with red and purple shading, gusts up to 75 mph, and a wind warning icon, divided by a curved white line.
Saturday 24 January 2026

On this day...

Historic Storm Éowyn arrives
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
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