Two or three centimetres of snow is enough to slow London down noticeably, and a heavy fall will close sections of track that run above ground, take buses off the steeper routes and put hundreds of flights out of the schedule. The Underground's deep tunnels carry on almost untouched. Everything with sky above it is the part to worry about.
Snow that settles is not an annual event here. The Met Office puts the UK average at 13.0 days of lying snow a year across the 1991 to 2020 period, and says most of that is in Scotland and on high ground; London sits at the very bottom of the range. Some winters produce nothing at all.
When it does come, the city reacts out of proportion, and visitors who are used to snow find that baffling. Our guide to London in winter covers the season in general. This page is about the two or three days themselves: what keeps moving, what does not, and whether any of it should change what you had planned.
Snow in London: the working numbers
- Lying snow, UK average
- 13.0 days a year (Met Office, 1991–2020). London is well below it
- When snow falls
- Air temperature below 2°C; the heaviest falls come between 0°C and 2°C
- Air frost at Heathrow
- Six or seven nights in each winter month (Met Office averages)
- Met Office warnings
- Yellow, amber, red, issued up to seven days ahead for snow and ice
- Cold-Health Alerts
- UKHSA, England, focused on 1 November to 31 March
- Roads gritted by TfL
- 580 km of Red Routes, with a fleet of 39 gritters
- Salt held by TfL and the boroughs
- More than 100,000 tonnes
- Unaffected
- Deep-level Tube tunnels, museums, theatres, most of the West End
Why so little snow causes so much trouble
The physics is against London. The Met Office notes that precipitation falls as snow when the air is below 2°C, and that in Britain the heaviest snowfalls tend to come when the air is between zero and 2°C — the wet, heavy kind that sticks to overhead wires and points, then compacts into ice underfoot. Powder snow that blows off a railway line and stays dry is a Scottish problem, not an English one.
The second factor is frequency. Take the Met Office thirty-year figures measured at Heathrow: six or seven nights of air frost in each of the three winter months, and average daily highs above 8°C in all of them. A city with that climate does not own snow tyres, does not keep its pavements clear as a matter of habit, and has a fleet of buses and trains designed for rain.
The third is that everything here is running at capacity. A twenty per cent reduction in the number of trains on a line that is already full at 8am does not produce a twenty per cent delay; it produces a platform nobody can get onto.
The two warning systems, and which one to read
The Met Office issues warnings for snow and ice through the National Severe Weather Warning Service, up to seven days ahead, coloured yellow, amber or red. The colour combines how bad the effects could be with how likely they are, which is why a yellow warning sometimes covers serious disruption that is not certain.
For a visitor the useful part of each warning is the "what to expect" section, which names the specific effects: untreated pavements, delays to road and rail, power cuts. An amber warning is the point at which the Met Office suggests changing plans. A red warning is rare in London and means dangerous conditions.
Cold-Health Alerts are issued separately, by the UK Health Security Agency together with the Met Office, in the same three colours, focused on the period from 1 November to 31 March. These are aimed at the health and care sector rather than at travellers, but they are published openly and are a good general signal of how severe a cold spell is expected to be.
The warning is for a region, not for a street. A yellow snow warning drawn across the south-east routinely covers London when the snow itself falls mainly on the Chilterns and the North Downs. Look at the map on the warning and at the hour-by-hour forecast for your own postcode before you cancel anything.
The winter machinery under the Tube
Transport for London has a long-standing set of cold-weather procedures, and the deep Underground is the easiest part of the network to keep running because most of it is not exposed to the weather at all.
TfL runs de-icing trains overnight to keep the rails clear, heats and checks the points that operate junctions, and treats station platforms so that people can stand on them. On the DLR, points heaters run and staff grit the platforms. London Overground uses trains fitted with de-icing tanks to keep the conductor rail free of ice, with rail heating installed at key locations and station surfaces gritted.
The bicycle hire scheme is designed to stay open in all weather, and TfL's winter plan says as much, though whether you want to cycle on a compacted-snow cycle lane is a separate question; our guide to cycling in London covers the network. The cable car has operational limits and will not run in some conditions.
What stops first
The order is fairly predictable. Above-ground sections of the Underground go before tunnels: the outer ends of the Metropolitan, District, Central and Piccadilly lines, where trains sit in exposed sidings overnight. The DLR and the Overground are entirely or largely above ground and are affected early. Our guide to the Underground explains which parts of each line are in the open.
Buses are next, and they go route by route rather than all at once. London is hillier than it looks — Crystal Palace, Highgate, Muswell Hill, Sydenham, Shooter's Hill — and operators withdraw services from steep roads before they become impassable, sometimes running a shortened version instead. Check the live status rather than the timetable; our guide to London buses explains where to look.
Mainline trains out of London suffer most of all, because a problem anywhere on a long route reaches the London terminus. Southeastern, Southern and Thameslink services run on third-rail electrification, which ices up. Expect cancellations and a reduced emergency timetable rather than minor delays, and do not plan a day trip out of London on a snow day.
Flights: check before you leave the hotel, not at the airport
Airports in Britain do not usually close for snow, but they do reduce the number of movements they can handle, because every aircraft has to be de-iced and runways have to be cleared in rotation. Airlines respond by cancelling flights in advance, sometimes the night before, to keep the remaining schedule workable.
The practical rule is that the airport's own website and your airline's app will know before you do. Never set out for Heathrow on a snowy morning without checking your specific flight, and if it has gone, rebook from where you are rather than from a queue in a terminal.
Allow far more time than usual for the journey out. The Piccadilly line and the Elizabeth line are more reliable than the roads in these conditions, and both run to Heathrow. Our comparison of late-night and early-morning airport transport is worth reading if your flight is at dawn.
Pavements, ice and the reason nobody clears them
The pavements are where visitors actually come to grief, because the day after the snow is worse than the day of it. Melted snow refreezes overnight into black ice, and London does not have a culture of householders clearing the frontage of their buildings.
The government's position, published on GOV.UK, is that you can clear snow and ice from pavements yourself and that it is unlikely you would be held responsible if someone were injured on a path you had cleared carefully. Its advice is to do it early in the day while the snow is loose, never to use water because it refreezes into black ice, and to use salt, or ash and sand for grip. Councils publish which roads and pavements they grit.
For a visitor this means two things. Walk on the gritted main roads rather than the quiet side streets, which look prettier and are lethal. And go slowly on station steps and bridge approaches, which stay icy longest.
Do not trust a clear-looking pavement at eight in the morning. A surface that thawed in yesterday's afternoon sun and refroze overnight is ice with no visible snow on it. Most snow-day injuries in London happen on the second and third mornings, not during the fall itself.
Should you change your plans?
Usually not. Almost everything visitors come to London for is indoors and unaffected: the museums and galleries open as normal, the West End theatres very rarely cancel, the restaurants are quieter and easier to get into. Our guide to what to do on a rainy day works just as well in snow.
What is worth moving is anything that depends on travel time, height or an outdoor queue. Push a day trip to later in the week. Swap a river cruise or a viewing platform for a gallery, because the view will be a grey wall anyway. Do not book a timed entry at an attraction that needs two changes of train to reach.
If you are caught out mid-journey, the tactics are the same as during a strike: move earlier or later than the peak, walk the short hops rather than waiting, and accept a longer route on a line that is underground. Our page on visiting during a strike covers how to rebuild a day around a broken network, and driving is the worst of all the options, as driving in London explains even in good weather.
The half-day that is genuinely better in snow
London under snow is briefly one of the best-looking cities in Europe, and almost nobody is out in it. If you have a morning to spend, spend it in a park.
The high ground gives you both the view and the sledging: Primrose Hill above Regent's Park and Parliament Hill on Hampstead Heath are the two classics, and every child in north London is on one of them by 10am. Our guide to Regent's Park and Primrose Hill has the approaches. Richmond and Greenwich are quieter and just as good.
The big attractions are unusually empty on a snow morning, because the day-trip coaches do not arrive and the school groups cancel. If there is something you had written off as too busy, this is the day to try it. The outdoor ice rinks keep running, and a snowy December improves them considerably.
What to wear when you packed for rain
Most visitors arrive with a waterproof coat and city shoes, which is right for London ninety per cent of the winter and wrong for these three days. The coat is fine. The shoes are the problem, because leather soles on compacted snow are close to useless.
If you are going to be out for a day, buy a pair of cheap rubber-soled boots rather than trying to manage; every high street has somewhere selling them, and you will use them again in the rain. Add gloves and a hat, which matter more than a heavier coat, since buildings and the Underground here are heated hard and you will be taking layers off indoors constantly. Our guide to what to pack for London covers the rest, and London weather explains the ordinary winter you are much more likely to get. The opposite extreme, which is now the more common disruption, is covered in London in a heatwave. If a cancelled flight or a lost day is going to cost you money, check what your policy covers before you travel; see travel insurance and healthcare cover.
Frequently asked questions
How often does it snow in London?
Snow falls in most winters but settles rarely. The Met Office gives a UK average of 13.0 days of lying snow a year for 1991 to 2020, and notes that most of it is in Scotland and in mountainous areas. London is at the bottom of the national range, and some winters produce no lying snow at all.
Does the London Underground run in snow?
The deep tunnelled sections run almost normally, because they are not exposed to the weather. The outdoor stretches at the ends of several lines are affected. Transport for London runs de-icing trains overnight, heats the points at junctions and treats platforms, but expect a reduced service above ground.
Do flights get cancelled at Heathrow when it snows?
Often, yes. Airports stay open but handle fewer aircraft because everything has to be de-iced and runways cleared in turn, so airlines cancel flights in advance to protect the rest of the schedule. Check your specific flight on the airline's app before leaving for the airport.
Are London pavements gritted?
Main roads and priority routes are, by Transport for London on its Red Routes and by the boroughs elsewhere; residential pavements largely are not. GOV.UK says individuals may clear snow and ice from pavements themselves and advises using salt rather than water, which refreezes into black ice.
Is it worth visiting London if snow is forecast?
Yes. Museums, galleries, theatres and restaurants are unaffected and noticeably less crowded, and the parks are at their best. Move anything that depends on a long train journey, a rooftop view or an outdoor queue, and allow considerably more time to reach an airport.
Sources
- Met Office - Snow: how it forms and how much the UK gets (checked September 2026)
- Met Office - Weather warnings guide (checked September 2026)
- UK Health Security Agency - Cold-Health Alerting system: overview (checked September 2026)
- Transport for London - Winter weather plans: de-icing, points heating and gritting (checked September 2026)
- GOV.UK - Clear snow from a road, path or cycleway (checked September 2026)
- Met Office - Long-term averages for the Heathrow station, 1991-2020 (checked September 2026)