Rush-hour commuters could face hazardous driving conditions and delays as a fresh band of thick fog blankets the UK on Monday.The Met Office issued its second consecutive severe weather warning for fog, after the misty visibility-reducing conditions blighted the south of the country overnight on Saturday.Greg Dewhurst, a Met Office meteorologist, said the new severe weather warning they have issued covers southern parts of England and Wales and is valid until 10am on Monday. Want to know what’s happening this coming week? It’s all go, with #fog, frost, rain, wind and yes, some #sunshine too…here are the details pic.twitter.com/L2DeoVaaKv— Met Office (@metoffice) December 18, 2016 A yellow severe weather warning for #Fog has been issued: https://t.co/dJ1l6CLuuO Stay #weatheraware @metofficeuk pic.twitter.com/qWSCumFUHx— Met Office (@metoffice) December 18, 2016 A van driver negotiates thick fog in Wimbledon, as motorists were warned of difficult conditionsCredit:Amer Ghazzal/REX/Shutterstock “For the morning there could be some tricky driving conditions, the fog will be in and out – you could be fine driving along and the next minute come across this thick fog,” he said.”It is worth drivers being aware first thing in the morning,” he said, adding that “some dense patches are definitely possible”. Show more Over the weekend, Gatwick and Heathrow airports warned their passengers they could face delays and cancellations because of the “foggy conditions”.And as the next batch of fog rolled across the South West, southern Wales, the Midlands and parts of the South East, Mr Dewhurst said visibility in Bournemouth was around 200 metres and 400 metres in Exeter. However, passengers travelling from England’s main airports escaped delays and cancellations on Monday morning after a blanket of fog over southern and central parts of the country began to lift.There were fears that flights might be badly hit after the Met Office issued a severe weather warning for fog for a large swathe of land stretching from the South Coast to the Vale of York and East Anglia.But forecasters said the fog had eased overnight to a lighter mist in some areas and would continue to break up throughout the day.Both Heathrow and Gatwick Airports warned passengers on their websites of delays and cancellations overnight, but by Monday morning Gatwick said “reasonable” visibility meant there was no impact on flights, while Heathrow was a little misty with just a few knock-on effects from delays at the weekend. The Met Office warning advised people to “be aware of potential delays and hazardous driving conditions”.Mr Dewhurst said that in terms of temperatures on Monday morning “it could be on the cold side” and a “little bit frosty in one or two places”.”But that is more likely in countryside, towns and cities will be holding up around four or five degrees – which is about average,” he added.”It will be quite a dull start to the day elsewhere as well – with generally cloudy conditions and some light patchy rain.” Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.