Why Dense Fog Warnings Are Causing Travel Delays Across the UK
Heavy morning fog has triggered yellow weather warnings across large regions of the UK. The Met Office warned that dropping visibility could disrupt morning commutes across roads, railways, airports, and ferry services. The warnings affect millions of people across England, Wales, and Northern Ireland.
What happened
- Saturday night
Thick fog contributes to major crashes in England, including a 30-car pile-up on the M20 in Kent and a 19-vehicle collision on the A303 in Hampshire [1].
- Sunday, 18:00 UTC
A yellow fog warning takes effect across South East England, East Anglia, the Midlands, and sections of Yorkshire [2].
- Sunday, 22:00 UTC
Forecasters issue a second yellow fog alert for western areas of Northern Ireland, including Derry, Enniskillen, and Newry [2].
- Monday, 10:00 UTC
The weather alert covering Northern Ireland comes to an end [1] [2].
- Monday, 11:00 UTC
The broader yellow warning for England and Wales is scheduled to expire [1] [2].
What you need to know
Visibility can fall below 50 to 100 metres in affected regions, making driving hazardous [1] [2].
Buses, trains, flights, and ferries face potential delays or cancellations [1] [2].
Airports like London Heathrow have advised travelers to check flight statuses and leave extra travel time [1].
Drivers are advised to check road conditions, maintain extra stopping distance, and switch on fog lights when needed [1] [2].
It is not yet clear whether persistent fog patches will remain past midday in certain localized areas [1]. The full extent of public transit and flight cancellations has not been confirmed [1] [2].
Background
Fog forms near the ground when air cools down and water vapor condenses into tiny liquid droplets. While mist leaves visibility above 1,000 metres, dense fog drops sightlines much further, creating significant hazards for drivers and pilots [1].
Clearer skies over the weekend allowed heat to escape quickly, bringing overnight ground frost, chilly temperatures in the low single digits, and widespread fog across England and Wales [1].
Airports experience reduced capacity during thick fog because landing aircraft require larger spacing intervals for safety, leading to knock-on flight schedule disruptions [1].
Questions people ask
Which regions fall under the fog alerts?
The alerts cover wide swathes of England and Wales—including London, Birmingham, and parts of Greater Manchester—along with western Northern Ireland [1] [2].
When are the fog warnings expected to lift?
The warning for Northern Ireland expires at 10:00 on Monday, while the alert for England and Wales ends at 11:00 [1] [2].
Why does fog cause flight delays?
When visibility is poor, air traffic regulations require wider spacing between landing airplanes, which slows down airport arrivals and departures [1].
Where this came from
Found through Google Trends and drafted with AI from at least two cited sources. Published automatically after passing our automated checks for sources, wording and safety. It may not have been reviewed by a person yet. Report a correction.