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
The monsoon has India firmly in its grip. Severe thunderstorms. . . Thursday 9 July 2026
Satellite map of South Asia showing the weather situation over India. An arrow marks a low-pressure system over western and central India, which is causing heavy showers and thunderstorms. Thick clouds and rainfall extend across large parts of India as far as the Himalayas and into Bangladesh. Over Pakistan and south-eastern Iran, however, it is mainly sunny and hot, with temperatures exceeding 40 degrees.
Thursday 9 July 2026

Severe thunderstorms

The monsoon has India firmly in its grip
Very high UV levels during the heatwave. Sun cream at the ready!. . . Wednesday 8 July 2026
Split graphic showing a UK temperature map with hot conditions across England and Wales, temperatures reaching 32 °C near London, and a UV warning icon on the left, alongside a person applying sunscreen in bright sunshine on the right.
Wednesday 8 July 2026

Sun cream at the ready!

Very high UV levels during the heatwave
Summer in full flow. Your weather - Your shots. . . Sunday 5 July 2026
Split image showing golden crepuscular rays streaming through sunset clouds over the countryside on the left, and glowing blue noctilucent clouds above silhouetted trees and traffic lights at twilight on the right.
Sunday 5 July 2026

Your weather - Your shots

Summer in full flow
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
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
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