Impacts
Last updated 15 November 2026
Weather Footprints is not a weather warning service. Footprints show where weather could cause problems, so that you can plan ahead; they are not official warnings and should not be used in place of them. Always follow the warnings of your national weather service: the Met Office in the UK and Met Éireann in Ireland.
Weather only matters for what it hits. The same snowfall means far more on a busy motorway than on an empty moor, and the same gale far more where it can bring trees down onto power lines and railways.
For each kind of weather (see Risks) we look at what is in its way, and count only the things that weather really affects: fog matters on roads and at airports, but hardly at all to power lines; wind and lightning bring power lines down, but fog does not.
Places with more in the way score higher on the maps, and quiet places lower: a busy place can make a footprint up to two steps more serious, and the emptiest countryside up to two steps less.
At a glance: what each kind of weather counts.
| Snow | Rain | Wind | Storms | Frost | Fog | |
|---|---|---|---|---|---|---|
| People | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Main roads | ✓ | ✓ | ✓ | ✓ | ✓ | |
| Roads over high ground | ✓ | ✓ | ||||
| Railways | ✓ | ✓ | ✓ | ✓ | ✓ | |
| Power lines | ✓ | ✓ | ||||
| Electricity substations | ✓ | ✓ | ✓ | |||
| Hospitals | ✓ | ✓ | ||||
| Schools | ✓ | |||||
| Care homes | ✓ | ✓ | ✓ | |||
| Airports | ✓ | ✓ | ✓ | ✓ | ||
| Homes and roads that flood | ✓ |
What we count
People
Where people live. Every kind of weather counts this, because the more people there are in the weather's way, the more lives it can disrupt.
How weather affects it. Weather affects people directly, through slips on ice, journeys that go wrong, and homes that flood or lose their power, and through the services they rely on.
Where it matters most. Towns and cities count most, and the quietest countryside least.
Affected by: every kind of weather.
How we count it. We use estimates of how many people live in each small area of the UK and Ireland.
Main roads
Motorways and A and B roads, which keep people, goods and the emergency services moving.
How weather affects it. Snow and ice make them slippery and can block them; heavy rain floods dips and underpasses; fog hides hazards until the last moment; and high winds bring down trees and blow over high-sided vehicles.
Where it matters most. Busy routes in and around towns, and the long main roads that link them.
Affected by: snow, heavy rain, high winds, frost & ice and fog.
How we count it. We measure how much main road runs through each area, from a free, detailed map of the UK and Ireland made by volunteers (OpenStreetMap).
Roads over high ground
Main roads that climb over hills and moors.
How weather affects it. Snow and ice arrive first and stay longest on high ground, so these roads are often the first to close, sometimes leaving drivers stranded.
Where it matters most. The roads over the Pennines, the Scottish Highlands, Wales and the moors of the south-west.
Affected by: snow and frost & ice.
How we count it. We count the main roads that run over high ground, as well as counting them as main roads.
Railways
Railway lines, which carry commuters to work and goods across the country.
How weather affects it. Snow and ice freeze the points and block the line; heavy rain floods cuttings and can cause landslips; gales blow trees onto the track; and fog makes the work of keeping trains moving a little harder.
Where it matters most. Busy lines around cities, and the main lines between them.
Affected by: snow, heavy rain, high winds, frost & ice and fog.
How we count it. We measure how much railway runs through each area.
Power lines
Overhead electricity lines, carrying power across the country and out to homes.
How weather affects it. Gales blow trees and branches onto overhead lines, and lightning strikes them. Either can leave homes and businesses without power, sometimes for days.
Where it matters most. The countryside, where much of the electricity reaches homes on overhead lines that run past trees.
Affected by: high winds and thunderstorms.
How we count it. We measure how much overhead power line runs through each area.
Electricity substations
Where power is passed on from the main network to homes and businesses.
How weather affects it. Flood water can force a substation to shut down, and storms and lightning can damage one. When a substation fails, a whole area can lose its power.
Where it matters most. Wherever there are many of them, which is mostly in and around towns.
Affected by: heavy rain, high winds and thunderstorms.
How we count it. We count the substations in each area.
Hospitals
Where patients are cared for, and where staff and ambulances need to come and go at all hours.
How weather affects it. Ice brings a rush of falls and broken bones, and makes it harder for staff and ambulances to get in. Thunderstorms can cut the power.
Where it matters most. Towns and cities, where most hospitals are.
Affected by: thunderstorms and frost & ice.
How we count it. We count the hospitals in each area.
Schools
Where children travel in and out every day.
How weather affects it. Fog makes school runs and school buses more dangerous, with children walking, waiting and being dropped off when drivers cannot see far.
Where it matters most. Towns and villages, wherever there are many schools.
Affected by: fog.
How we count it. We count the schools in each area.
Care homes
Where many of the people most at risk from cold, ice and disruption live.
How weather affects it. Residents are especially at risk from cold and falls, and snow and floods can stop carers, food and medicine getting through.
Where it matters most. Towns and the countryside alike, wherever there are many care homes.
Affected by: snow, heavy rain and frost & ice.
How we count it. We count the care homes in each area.
Airports
The larger airports of the UK and Ireland.
How weather affects it. Fog and snow close runways or slow down landings; strong gusts and thunderstorms delay and divert flights.
Where it matters most. Around each airport.
Affected by: snow, high winds, thunderstorms and fog.
How we count it. We count the larger airports in each area.
Homes and roads that flood
Homes and major roads in places that official flood maps show are prone to flooding when it rains hard.
How weather affects it. In these places water collects quickly in heavy rain, flooding homes and closing roads. Where the flood maps exist, heavy rain is judged mostly by what lies in them.
Where it matters most. England, Scotland and Wales, where these maps exist.
Affected by: heavy rain.
How we count it. We count the people who live, and the major roads that run, in the mapped flood areas, from the official surface-water flood maps.