The orchestra has issued another weather warning for fog later this week – but said the UK is in for “the worst” of the cold snap.
The Met Office said there would be difficult driving conditions in parts of England, while freezing temperatures could see untreated surfaces become slippery.
A yellow weather warning is in place for Sunday between 2am and 11am, with thick fog expected to see from Yorkshire to East Anglia.
This means travel delays and flights can be cancelled.
A “moderate” air pollution warning has also been issued by Mayor Sadiq Khan in London, where hazy conditions are causing poor dispersion of vehicle emissions.
He added: “On Sunday, along with extremely cold temperatures, we are also expecting moderate to high levels of air pollution.
“We all need to be careful in the next few days. I am urging Londoners to walk, cycle or take public transport, avoid unnecessary car journeys, prevent engine idling and not burn wood or garden waste, all of which contribute to high levels of pollution . This is especially important to protect people who are more sensitive to high pollution.”
But Met Office meteorologist Craig Snell said the worst of the cold spell was over, with temperatures expected to rise across Britain next week.
Mr Snell said: “Looking at the severe front, next week, it’s looking pretty benign.
“We’re starting to see the risk of fog subside and temperatures are generally around where they should be.
“We’ll probably lose some really hard frosts. In terms of snow and ice, it certainly looks like we’re past the worst.”
“We generally have to keep an eye on the risk of fog this winter, although the main threats from it are starting to subside.”
Nighttime temperatures across the country are still forecast to be sub-zero during the weekend, and will climb to highs of around 5C in the southeast and 10C in the north.
Mr Snell explained that temperatures would be lower in the south – which is often warmer than other areas of the country – due to a change in wind direction to the north west.
The change will lead to an arctic blast that has swept across the UK over the past five days giving way to warm air from the Atlantic, but will take longer to reach southern regions.
Several sporting events have been canceled and travel canceled on Saturday due to the severe cold.
The Sky Bet Championship match between Blackpool and Huddersfield was postponed due to a frozen pitch and a race meeting at Haydock was canceled due to an icy track.
CalMac Ferries, which operates services from mainland Scotland to the islands off its west coast, also canceled sailings due to the weather.
National Rail said there was disruption to trains due to failure of points between Wessex and three bridges in Brighton, Hove and Sussex, but did not specify whether this was caused by snow.
It comes after temperatures fell to minus 10 degrees Celsius amid icy and snowy conditions in parts of the UK this week.
Drumnadrochit near Inverness in the Highlands recorded minus 10.4C in the early hours of Thursday, making it the coldest temperature ever recorded.
Manchester Airport was also forced to close both of its runways for a period due to the heavy snow.
(translate to tag) The Met Office