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

    Rolling haar: A sea of fog on the Ligurian coast

15:00
28 August 2023

Rolling haar
A sea of fog on the Ligurian coast

Can't get to the coast this Bank Holiday? Check out this sea fog instead which affected large stretches of the Ligurian coast earlier this year.

Sea fog, known also as haar in the UK and Ireland, forms under certain conditions and is best observed between late winter and late spring.

This is because during spring, the sea reaches its lowest temperatures, while warmer air moving in becomes more common. Sea fog requires the movement of a warm air mass over a cold sea surface.

sea fog infographic

The warm air passing over this colder surface then cools and condenses, like when a person breathes warm air onto cold glass, forming a dense layer of fog or low cloud.

If there is a strong anticyclone (high pressure system) in place, which suppresses convection and forces air to subside, the fog that forms will be more robust.

Weather & Radar editorial team
More on the topic
Severe weather in holiday spots. Crete and Spain. . . Thursday 1 October 2026
Weather maps showing the risk of storms and flooding in Greece, as well as heavy rain and thunderstorms on Spain’s east coast.
Thursday 1 October 2026

Crete and Spain

Severe weather in holiday spots
First autumn views of the season. Your weather - Your shots. . . Sunday 27 September 2026
Split image showing a vivid double rainbow over green fields beside a sunny marina filled with boats beneath blue skies.
Sunday 27 September 2026

Your weather - Your shots

First autumn views of the season
First taste of winter in the Alps. White mountain peaks. . Weather Videos. Friday 25 September 2026
Winter scenery in the Alps along the Großglockner High Alpine Road
Weather VideosFriday 25 September 2026

White mountain peaks

First taste of winter in the Alps
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
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
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
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