The Met Office has warned of travel chaos and possible flight cancellations on Saturday as visibility plunges to just 50 yards in some areas.
Drivers should expect ‘hazardous driving conditions’ and slower journey times, with delays to bus and train services expected.
‘There is a chance of delays or cancellations to flights,’ according to the Met Office.
Elsewhere today the fog will slowly lift to low cloud and there will be a ‘chilly feel’. The Met Office said: ‘Most parts will be dry with large amounts of cloud and some sunny intervals. A few showers are expected to affect western parts later.’
It comes amid a risk of freezing conditions until next Monday, with temperatures set to plummet as low as -4C (24F) in parts of the country and people urged to check on their vulnerable neighbours.
Bookmaker Coral has made it odds on at 4-5 that the UK will record its coldest January ever, while also making it even shorter odds of 1-2 on snow falling in London this month.
Temperatures are set to plummet this weekend with lows of 0C in Wales and west England as a fog warning is issued for London, Birmingham and the East of England. Pictured, fog in the Oxfordshire countryside
Met Office spokesperson Stephen Dixon told Metro he was not expecting widespread snow, but for a light dusting on high grounds in Scotland, which is expected at this time of year. Pictured, a pony in Dundsen, Oxfordshire
From Thursday afternoon, the Met Office warned the West Midlands, East Midlands, East of England, London, South East England and South West England regions will experience cold weather.
Met Office Deputy Chief Meteorologist Dan Rudman said: ‘Overnight minimum temperatures are possibly getting to -4C in some rural areas, but widespread below-freezing conditions elsewhere overnight in the following days.
‘This will result in some harsh frosts and possible freezing fog in some places.’
Agostinho Sousa, Consultant in Public Health Medicine at UKHSA, added: ‘As we continue to experience very low temperatures this winter it’s important to remember to check on those who are more vulnerable to cold weather, such as elderly or frail friends and family, especially if they live alone or with a serious illness.’
She said the ‘most vulnerable’ should heat their homes to at least 64F (18C) particularly if they have reduced mobility, are 65 and over, or have a health condition.
She also advised people to wear shoes with good grip if they need to go outside during the cold weather.
Met Office spokesperson Stephen Dixon told Metro he was not expecting widespread snow, but for a light dusting on high grounds in Scotland, which is expected at this time of year.
Meanwhile, Coral’s Harry Aitkenhead said: ‘With January still yet to reach its third week and temperatures forecast to sink extremely low as the month progresses, we now make it odds on to be the UK’s coldest ever.’
He added: ‘Londoners can expect snow this month with the white stuff falling firmly odds on according to our odds.’
A yellow fog warning has been put in place across London, Birmingham, the east of England and the north east
Drivers should expect ‘hazardous driving conditions’ and slower journey times, with delays to bus and train services expected. Pictured, Dunsden in Oxfordshire this morning
Elsewhere today the fog will slowly lift to low cloud and there will be a ‘chilly feel’. The Met Office said: ‘Most parts will be dry with large amounts of cloud and some sunny intervals. A few showers are expected to affect western parts later.’ Pictured, cars in Dunsden, Oxfordshire
Thick fog rolling in from the River Thames smothers the town of Gravesend in Kent
Fog is pictured in Gravesend, Kent, early on Saturday morning. Drivers were warned to expect low visibility
A walker is pictured in a park in Gravesend, Kent, amid a foggy start to the day on Saturday
The fountain in Gordon Gardens was difficult to see because of the fog over Gravesend, Kent, Saturday morning
Park runners gathered in Finsbury Park, London, on Saturday morning
The fog did not put off park runners in Finsbury Park on Saturday morning
A lone walker can barely be seen amid the fog in Finsbury Park, London, on Saturday morning
With the cold weather arriving as Britons face a crushing cost-of-living crisis, including increased costs on heating bills, the Government advised people to heat the living room during the day and the bedroom while going to sleep ‘if people can’t heat all the rooms they use’.
The UKHSA, which issued the cold weather alert, added: ‘Wearing a few thin layers is better at trapping heat than wearing one thick layer.
‘Having plenty of hot food and drinks is also effective for keeping warm.’
The predicted cold weather comes after Britons experienced a milder than usual start to the year and follows the UK’s warmest ever New Year’s Day when St James’s Park in London registered 16.3C (61.3F), beating the previous record of 15.6C (60.1F) set in Bude, Cornwall, set more than a century ago in 1916.
And that came after the country’s mildest New Year’s Eve on record the day before when Merryfield in Somerset reached 15.8C (60.4F), beating the previous high of 14.8C (58.6F) set in 2011 at Colwyn Bay in North Wales.