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
Your moment, your location, your weather. Capture the scene with us. . . Saturday 1 August 2026
Promotional graphic for the Weather & Radar app showing a smartphone recording a live weather video in Coventry, England, with a temperature of 27°C, zoom controls, a weather map overlay, and the headline “Weather live – capture your moment.”
Saturday 1 August 2026

Capture the scene with us

Your moment, your location, your weather
Floods and landslides in parts of Asia. An unusual monsoon. . . Wednesday 29 July 2026
Split image: On the left, flooded villages and fields can be seen in a vast landscape. On the right, a weather map of India shows heavy rainfall, along with a warning sign featuring a car in floodwater.
Wednesday 29 July 2026

An unusual monsoon

Floods and landslides in parts of Asia
Forest fires spread to south-east Europe. Heat and strong winds. . . Thursday 30 July 2026
Split image showing an active wildfire with flames and thick smoke on the left, and a wind forecast map of Greece on the right with gusts of 25–35 mph around the Aegean Sea, alongside a wildfire warning symbol highlighting elevated fire danger.
Thursday 30 July 2026

Heat and strong winds

Forest fires spread to south-east 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
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
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