The Met Office has issued a UK Met Office fog warning from 6pm on Sunday until 11am on Monday, covering large parts of the country as visibility falls and travel is put at risk. The warning takes in most of southern England, the Midlands and pockets of northern England and Wales.
Niamh Murray, a Met Office operational meteorologist, said the UK had a “perfect recipe” for dense fog. She said light winds, clear skies and long nights were helping it form, and that it could be stubborn to clear where temperatures drop low enough overnight.
Met Office warning areas
The warning excludes the south-west but includes most of southern England, the entirety of the Midlands and smaller areas in northern England and Wales. The Met Office said fog was expected in Liverpool, Sheffield, York, Cardiff and Wrexham, putting a long stretch of roads and rail links into the same overnight weather window.
Murray said: “We get a longer period of cooling and also the temperatures are much lower, so they’re much closer to the temperature that we need for the air to become saturated and therefore form fog.”
50 metres and flight risk
The Met Office said visibility may reduce to as little as 50 metres or less in parts of the UK, with bus and train services likely to be delayed. It also warned that delays and cancellations for flights in and out of the country are a possibility, which makes the overnight period the most important one for anyone travelling before the warning ends.
“Another thing that we need to form fog is quite light winds, not absolutely no winds. We just have the perfect recipe at the moment: light winds, clear skies, long nights, to allow that fog to develop. And particularly if we see the negative numbers, it can be quite stubborn to clear the next day,” Murray said.
South-west rain and drought
Murray also said rainfall after the fog could bring some relief in the south-west, where severe drought has been declared and is still enforced by the Environment Agency. She said very slow-moving rain could produce accumulations of 50 to 70mm, a separate weather pattern that could matter to areas already under water stress even as the fog warning remains the main short-term issue.
For travellers, the practical window is clear: the most difficult conditions are expected overnight into Monday morning, with the warning due to end at 11am. Anyone using roads, buses, trains or flights before then should expect the fog to be thick enough in places to slow journeys and reduce the reliability of timetables.
