Flood warnings in the UK come in three colours, and most people only learn the difference in the middle of a wet night, with water already creeping towards the back door. That is a bad time to start reading. The system is simple once you know it: yellow means prepare, amber means act, red means danger to life. Here is how each level works, who decides it, and what to do in the hours that follow.

Who decides when a flood warning goes out?

In England, the Environment Agency runs the flood warning service. Natural Resources Wales does the same job in Wales, SEPA covers Scotland, and in Northern Ireland warnings come from DAERA through NI Direct. They watch river levels, rainfall forecasts, tide tables and how saturated the ground already is, then issue warnings for a specific stretch of river, coastline or community rather than a whole county.

That distinction matters. A flood warning for the River Ouse in York does not mean a town twenty miles downstream is about to flood. It means a named area is at risk.

It is also worth knowing what the service does not cover. Small watercourses, ditches and surface water flooding after a sudden downpour are patchy, and some places have no warning at all. If you live somewhere that floods when a storm hits hard, an empty warnings page is not proof that you are safe.

Yellow: flood alert — flooding is possible

A flood alert is the earliest heads-up, often issued hours or a day or two ahead. The message is be prepared. Nothing is certain yet, and the alert may be cancelled as conditions change.

Use the time. Check the forecast and river levels for your area. Move anything valuable off the garage floor or out of the shed — paint, tools, bikes. Find your insurance documents. If you have a neighbour who is older, unwell or lives alone on a low-lying street, ring them now rather than later. Check your usual route to work or school too, because flood-prone roads often close early.

An alert is not a reason to panic. It is a reason to spend twenty minutes doing what you would rather not do at midnight.

Amber: flood warning — flooding is expected

This is the one that means business. A flood warning is issued when flooding is expected to affect homes, businesses or a main road. The official wording is blunt:

Flooding is expected. Immediate action required.

Act on it. Move furniture, electricals and anything sentimental upstairs or as high as they will go. Move your car to higher ground while the roads are still open. Fit flood barriers, gates or airbrick covers if you have them. Charge phones and power banks. Get pets to safety and, if you keep livestock, move them to higher ground.

If you are advised to turn off gas, electricity or water, do it — but only if the switches are safely reachable. Never wade through water to get to a fuse box.

This is also the moment to decide whether to stay or leave, and to tell someone what you have decided. Leaving in daylight, with dry roads and a full tank, is far easier than leaving at three in the morning with water across the driveway.

Red: severe flood warning — danger to life

Severe flood warnings are rare and serious. They are issued when there is a genuine risk to life: deep or fast-flowing water, a community about to be cut off, or defences expected to fail.

Do not wait to see it for yourself. Follow instructions from the emergency services, and if you are told to evacuate, go. Take medication, ID, your phone and a charger. Do not walk, swim or drive through floodwater. A foot of moving water can knock an adult off their feet, and it often hides open drains, debris and missing manhole covers. If someone is in immediate danger, call 999.

What each level asks of you

1. Yellow — be prepared. Check forecasts and river levels, move valuables, contact vulnerable neighbours, plan your route.
2. Amber — act now. Move possessions and vehicles, fit barriers, charge devices, prepare to leave, follow advice on utilities.
3. Red — protect life. Evacuate if told to, avoid all floodwater, call 999 in an emergency.
4. All clear — return with care. Warnings are lifted as river levels fall, but damaged roads and contaminated water linger. Wait for the go-ahead, and photograph any damage before you start cleaning up.

Flood warnings and weather warnings are not the same thing

The Met Office issues yellow, amber and red warnings too, which is where much of the confusion starts. Its warnings are about weather: heavy rain, gales, snow, ice. They cover broad areas and describe what the sky is likely to do.

Flood warnings come from the environment agencies and describe what water is likely to do to a particular place. The two often travel together — an amber rain warning over ground that is already soaked is exactly the sort of day that produces flood warnings the following morning. Watch both, but if you want to know whether your street is at risk, the flood warning is the one that answers the question.

Set this up before you need it

Twenty minutes now saves a great deal of stress later.

• Sign up for free flood warnings by phone, text or email through the relevant agency for your nation. You can register several addresses, including a relative's.
• Save the Floodline number, 0345 988 1188, in your phone.
• Check that your insurance covers flooding and that the policy is current. If you are unsure, speak to your insurer or a broker rather than assuming.
• Pack a small grab bag: medication, a torch, a charger, spare keys, documents in a waterproof bag, and pet supplies.
• Photograph every room and anything valuable. It takes minutes and helps enormously if you have to claim.
• Keep passports, deeds and irreplaceable items upstairs.
• Agree with your household where you would go and how you would get there.
• Talk to your neighbours. In most floods, the first knock at the door comes from someone who lives nearby, not from an official.

If you live in a flat or on an upper floor, you may be safer staying put — but you can still lose power, water and lift access. Keep a torch, bottled water and a charged phone close by, and check on anyone living in a basement or ground-floor flat.

A warning is only useful if it reaches you and you know what to do with it. Learn the three colours, register for alerts, and keep a simple plan somewhere you will actually find it.

Photo: koachphillips / Pixabay