
Met Office issues further warnings as visibility drops below 100 metres
AI-generated summary
High pressure across the UK has created ideal conditions for dense fog formation. Smoke particles from recent fireworks and bonfires have acted as condensation nuclei, increasing fog density.
Dense fog disrupted travel for many this morning and is likely to cause further disruption on Tuesday.
A Met Office warning for much of England and eastern Wales expired at 11:00 GMT on Monday. An additional fog warning for Northern Ireland ended at 10:00 GMT.
An area of England and Wales stretching from Canterbury to Cardiff, Hull to St Asaph and Southampton to York, and including London, Birmingham and parts of Greater Manchester was impacted.
The Met Office has issued a further warning for fog from Monday evening into Tuesday morning.
Heathrow Airport has advised anyone driving there to allow extra time for their journey.
"We advise passengers to check with their airline before leaving home and to drive with care," it said on X, external.
Part of M40 southbound has been shut after crash between junction 1A near Gerrards Cross, Buckinghamshire, and junction one for the M25 link road.
Thick fog already blanketed parts of England and Wales on Saturday night, making an FA cup match between Altrincham and Notts County less of a spectator sport.
It also caused a 30-car pile-up on the M20 in Kent, leaving two people seriously injured, as well as a 19-car collision on the A303 in Hampshire.
The fog will gradually lift through Monday morning, although some patches could linger into the afternoon.
The Met Office has issued another yellow warning for fog from Monday evening across east and north-east Wales, parts of the Midlands, East Anglia and southern areas of Northern England.
It comes into effect from 18:00 until 10:00 GMT Tuesday.
The fog will once again become dense in places with the visibility dropping below 100 metres.
Difficult travel conditions should be expected on the roads with some delays to other transport also possible.
With a large area of high pressure across the UK, conditions are ideal for the formation of dense fog.
Temperatures overnight into Monday morning dropped to around 3 to 5C across England and Wales which meant moisture at ground level condensed into water droplets, creating cloud - which is essentially fog.
Light winds then meant fog was able to get denser through the night, leading to visibilities less than 100 metres on Monday morning.
Fog has been particularly dense and widespread on Monday morning because there has also been a lot of fireworks and bonfires over the last few days.
Tiny smoke particules act as extra cloud condensation nuclei which allows more water vapour being able to turn into droplets.
Patchy fog could also develop outside the warning area in northern parts of the UK wherever skies remain clear for long enough.
Mist forms in the same way but is less dense, with visibility generally greater than 1,000 metres (1km).
AI outlook — possibilities, not facts
Fog warning in effect until 10:00 GMT Tuesday.
Very likely · Within days

Yellow weather warnings for dense fog are in effect across much of England, eastern Wales, and Northern Ireland, threatening travel disruptions and low visibility on Monday morning.

The Met Office has issued a yellow weather warning for dense fog across much of England and Wales from Sunday evening to Monday morning. Forecasters warn of potential travel delays, flight cancellations, and reduced visibility, while noting possible rainfall in the south-west.

Ecologists and conservationists warn that white-tailed eagle reintroductions in England and Wales threaten vulnerable seabird populations, dividing nature groups ahead of a licensing decision.

Two buyers who recently purchased properties in Newport, Norfolk, have been advised by Great Yarmouth Borough Council to vacate their homes due to the imminent risk of coastal erosion.

A family of six beavers has been released into the Loch Ness catchment at the Dundreggan rewilding estate, marking their return 500 years after extinction in the area.

The polar vortex has weakened unusually early in November, potentially triggering the earliest major sudden stratospheric warming event on record. Scientists say this could bring colder, drier weather to Europe and the UK, complicating winter forecasts amid an exceptionally strong El Niño.