Weather guide

Flood warnings near an event site

Riverside fields, showgrounds and town centre markets can sit in a flood area. This guide sets out what the Environment Agency's three warning levels mean, what they do not cover and what GOV.UK says to do when one is issued.

The three warning levels

The Environment Agency issues warnings for flood alert areas and flood warning areas in England. Its data service lists three levels in force, plus a fourth for a warning that has just ended.

  • Flood alert: flooding is possible, be prepared.
  • Flood warning: flooding is expected, immediate action required.
  • Severe flood warning: severe flooding, danger to life.
  • Warning no longer in force: shown for about 24 hours after a warning ends.

Source: Environment Agency: Real-time flood-monitoring API reference

What the warnings cover

GOV.UK says the service gives warnings about flooding from rivers, the sea or groundwater, depending on the area. It does not give warnings for surface water flooding, sometimes known as flash flooding. A heavy rain forecast is the closer signal for that.

The service covers England. Scotland and Wales have their own flood warning services, run by SEPA and Natural Resources Wales.

Source: GOV.UK: Get flood warnings by text, phone or email

Sign up for the official warnings

The Environment Agency sends its warnings by text, phone or email to households and organisations at no charge. GOV.UK says you can also sign up by calling Floodline on 0345 988 1188, a 24 hour service.

The Environment Agency says its open data service has no guaranteed service level and should not be relied on for safety-critical applications. It says the data does not replace the channels it uses to warn the public. Any tool built on that data, Gustline included, sits alongside the official warnings rather than in place of them.

Sources: GOV.UK: Get flood warnings by text, phone or email; Environment Agency: Real-time flood-monitoring API reference

When a warning is issued

GOV.UK says a flood warning means flooding is expected. Its advice includes moving people and important items to higher ground, not driving through flood water and following advice from the council or emergency services, who may ask you to evacuate. A severe flood warning means there is a danger to life: call 999 if someone is in immediate danger and leave if the emergency services tell you to.

It also says to use your flood plan if you have one. For an event that means the site's emergency plan: who decides to close, how people leave and which routes stay above the water.

  • Do not walk, cycle or drive through flood water.
  • GOV.UK warns that flood water may contain sewage and hide rubbish, broken drains and uneven ground.

Source: GOV.UK: What to do before or during a flood

How Gustline helps

Gustline's flood alert reads the Environment Agency's live warnings for the flood areas within about 1km of your pin, from three days before your event opens until it closes. A flood alert is Yellow, a flood warning is Amber and a severe flood warning is Red. It covers England only and repeats the Environment Agency's caveat in every alert: sign up for the official warnings too. This uses Environment Agency flood and river level data from the real-time data API (Beta), under the Open Government Licence.

Gustline checks the Met Office site-specific forecast for the point you pin on the map, every six hours from a week out and every hour in the final three days. It compares the forecast gust with the rated limit you enter for each structure and checks the weather alerts you leave on for the event. When a level changes it emails and texts the people you choose. Every alert is logged with a timestamp.

Gustline is an early warning for planning. It does not replace checks on site on the day, the official warnings or your event's own plans.

Plans start at £19 for one event. A season pass is £99 a season and a year pass is £179 a year. It covers the UK only.

Set up alerts for your next event

Sources

Last updated 4 October 2026.

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