Flood Alert Vs Flood Warning Vs Severe Flood Warning: What Each One Means And What To Do

The three levels are used by the Environment Agency in England, Natural Resources Wales and SEPA in Scotland. This page explains what each level means, what to do, how much notice each usually gives, and what each does not mean. Floodline gives advice 24 hours a day on 0345 988 1188. If life is at risk, call 999.

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What Is The Difference Between A Flood Alert And A Flood Warning?

A Flood Alert and a Flood Warning differ in how certain flooding is and what is at risk. An alert means flooding is possible so you should prepare now, usually for land, minor roads and farmland. A warning means flooding is expected so you should act now, and homes and businesses can be affected.

The three levels side by side:

Source: Environment Agency, Flood alerts and warnings: what they are and what to do.

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What Does A Flood Alert Mean?

A Flood Alert means flooding is possible so you should prepare now. The Environment Agency issues one when forecasts show flooding may be possible from rivers, or high tides, surges or strong winds at sea. An alert is a signal to get ready, not a prediction that your home will flood.

When a Flood Alert is issued, the official advice is to:

1. Be ready to follow your flood plan.
2. Have insurance documents and any medications ready.
3. Avoid walking, cycling or driving through any flood water.
4. Move any livestock and farming equipment away from areas likely to flood.

An alert usually comes between 2 and 12 hours before flooding. Flood alerts are usually issued during waking hours where possible. During an alert, the land at risk is typically fields, recreational land and car parks; minor roads; farmland; coastal areas affected by spray or waves overtopping.

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What Does A Flood Warning Mean?

A Flood Warning means flooding is expected so you should act now. The Environment Agency issues one when forecasts show flooding is expected from rivers, heavy rain that will cause rivers to flash flood, or high tides and surges coupled with strong winds at sea. A warning means property can be affected, not only open land.

When a Flood Warning is issued, the official advice is to:

1. Protect yourself and your loved ones.
2. Move your loved ones, pets and valuables to a safe place.
3. Move to higher ground or the upper floor of a building.
4. Turn off the gas, electricity and water if it is safe.
5. Put flood protection equipment in place.
6. Do as the emergency services tell you, and help others if it is safe.

A warning usually comes 30 minutes to 2 hours before flooding. At risk are homes and businesses; railway lines and infrastructure; roads; coastal areas affected by spray or waves overtopping; flood plains, including caravan parks and campsites; major tourist and leisure attractions.

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What Does A Severe Flood Warning Mean?

A Severe Flood Warning means flooding could cause danger to life and significant disruption to communities. It is the highest level, issued when flooding threatens life and communities. If you are in immediate danger, call 999.

When a Severe Flood Warning is issued, the official advice is to:

1. Stay in a safe place.
2. Be ready to evacuate your home.
3. Do as the emergency services tell you.
4. Call 999 if you are in immediate danger.
5. If caught in a flash flood, move to higher ground or the upper floor of a building if it is safe.

A Severe Flood Warning has no fixed notice period. Severe flood warnings can be issued before, during or after flooding. During one, the Environment Agency warns of deep and fast-flowing water; dangerous debris in the water; buildings collapsing or at risk of collapsing; communities unable to escape; infrastructure not working, like gas, electricity and water; the evacuation of lots of people.

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How Much Warning Does Each Level Give You?

A Flood Alert usually gives between 2 and 12 hours of notice before flooding, and a Flood Warning usually gives 30 minutes to 2 hours. A Severe Flood Warning has no set lead time, because it can be issued before, during or after flooding.

These are the usual times, not guarantees. Warnings are based on forecasts, and fast-rising rivers can give less notice. For an earlier view, the Environment Agency lets you check for flooding in the next 5 days.

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Who Issues Flood Warnings In England, Wales, Scotland And Northern Ireland?

Flood warnings are issued by the Environment Agency in England, Natural Resources Wales in Wales and SEPA in Scotland. No equivalent public flood warning service is listed for Northern Ireland, where NI Direct points residents to Met Office severe weather warnings.

Warnings in force now are listed on live flood warnings.

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How Do You Sign Up For Flood Warnings?

You sign up for flood warnings online with your nation's agency or by calling Floodline on 0345 988 1188. Messages arrive by phone call, text or email for the areas you choose.

• England: the Environment Agency states that the service is free.
• Wales: Natural Resources Wales's service is free, by text message, phone call and/or email; sign up online or on Floodline 0345 988 1188.
• Scotland: If your property is within an area covered by a SEPA flood monitoring system, you will be able to sign up to receive a targeted Flood Warning message for your local area. Otherwise, you receive a more general Flood Alert message for the wider geographical area, usually representing Local Authority boundaries.

What to prepare before a flood and what to do during one are covered in what to do in a flood.

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Sources (Verified 17 Sep 2026)