The Met Office has issued a yellow warning for fog covering 39 areas in England, with the alert taking immediate effect from 9pm today until 11am tomorrow.
The warning covers parts of the East Midlands, east England, London and south-east England, and the West Midlands.
Thick fog and low visibility
Forecasters have warned of low visibility conditions in the affected regions due to "thick fog". A Met Office forecast says: "Clearing skies over southeast England this evening and overnight, which has already led to the development of mist and some patchy fog, is likely to allow increasingly widespread and in places dense fog to form. Visibility could fall as low as 100m in some places."
The fog will gradually lift and clear to mist and haze during Saturday morning, persisting longest where visibilities are poorest early on.
Travel disruption possible
The Met Office said slower journey times with delays to bus and train services were possible. There is also a chance of delays or cancellations to flights.
The yellow warning for fog is in place until 11am on Saturday.
