The Met Office has issued a yellow warning for dense fog across much of England and eastern Wales running from 18:00 on Sunday until 11:00 on Monday. A separate yellow fog warning has also been issued for Northern Ireland and runs from 22:00 on Sunday until 10:00 on Monday. See warning details here, external.
The larger fog warning for England and Wales covers an area of the southern UK stretching from Canterbury to Cardiff, Hull to St Asaph and Southampton to York, and includes London, Birmingham and parts of Greater Manchester.
Visibility could fall to less than 50m in places, making driving difficult. Bus, train, ferry and flight services could also face delays or cancellations.