POSTCODE DISTRICT · ENGLAND

Brighton BN1 postcode area

Read the preparedness conclusion for BN1 in Brighton, check which council figures apply and find the official warning service for this location.

DISTRICT REPORT SCOPE

Area evidence, not a full-postcode grade

The BN1 prefix covers multiple addresses and may cross council or warning-area boundaries. The 0–6 Data & Preparedness Score below counts documented sources for this district. It is separate from the conditional A–G disruption grade on a full-postcode report.

A–G grade for BN1: not assessed at district level. A complete postcode is needed to check live utility and road incidents and listed emergency-care distance. A grade appears only when all three inputs can be scored. How the full-postcode grade works.

Population density compared with the UK

UK average: 287 residents/km². Figures below cover the named councils.

Brighton and Hove3,431 residents/km²UK council density percentile: 85/100
Lewes351 residents/km²UK council density percentile: 35/100
Mid Sussex490 residents/km²UK council density percentile: 43/100

ONS mid-2025 population estimates · MYE5

Preparedness conclusion for BN1

A Brighton address can fall under more than one council, so resolve the full postcode first.

Brighton and Hove is 3,144 residents/km² above the UK average of 287 residents/km². Lewes is 64 residents/km² above the UK average of 287 residents/km². Mid Sussex is 203 residents/km² above the UK average of 287 residents/km².

The directory associates BN1 with Brighton and Hove, Lewes and Mid Sussex. These authority figures describe different geographic areas. The prefix cannot assign a single council density or tell you whether a warning for part of the coast also affects an inland address.

Check current flooding in England

Local flood evidence for BN1

Recorded flooding

An Environment Agency evidence review summarises Brighton and Hove’s investigation into February 2014 groundwater flooding in Patcham and Portslade, including impacts on basements. Patcham is the local example relevant to the wider BN1 context. It illustrates a different type of flooding from a coastal or intense-rainfall incident.

Environment Agency review of the February 2014 Patcham investigation

Official warning area

The Environment Agency publishes a groundwater warning area for Old London Road in Patcham. That named area cannot be used as a warning for every BN1 address. The directory also associates BN1 with Brighton and Hove, Lewes and Mid Sussex, so check the mapped area and authority for your full postcode.

EA groundwater warning area for Old London Road, Patcham

Data & Preparedness Score 6/6

All three evidence checks meet the highest level for this report. The score describes the evidence available in this report. It does not measure risk, safety or personal readiness.

Warning coverage 2/2: A named official warning or alert area is documented locally. Check the mapped boundary for your address.
Official guidance 2/2: Local authority or regional preparedness guidance is linked below.
Data completeness 2/2: Council density is available. A local flood record is documented.

How the district score is calculated

Warning coverage earns 2 points for a documented local warning area, 1 for an official service link and 0 when no source can be identified. Guidance earns 2 for a local authority or regional preparedness link, 1 for UK guidance and 0 when neither is available.

Data completeness earns 2 points when council density and a documented local flood record are both available, 1 for either and 0 for neither. The three scores are added. The number or severity of current warnings does not change the score.

Emergency information for BN1

Save the official source for the address where you will be staying. If a journey spans inland and coastal locations, check both endpoints and the transport operator for the route.

Brighton and Hove’s flood risk management plan sets out the local flood context and routes to official sources. If your BN1 address is outside Brighton and Hove, use the authority returned for the full postcode. Check the current instructions for the affected street or building during an incident.

Check a full BN1 postcode

Enter the complete postcode, including its final three characters, to see the nine-indicator evidence breakdown, any supported provisional A–G grade, local incident results and a check against official flood-warning boundaries.

How the nine indicators apply

A district prefix covers many full postcodes. This page has no live A–G disruption grade and does not assess war or nuclear risk. Enter a complete postcode above to see the nine-indicator breakdown for its returned location.

Can contribute to a full-postcode grade: Infrastructure: matched electricity or water incidents where covered. Medical resources: straight-line distance to a listed emergency department. Road access: nearby active TfL events where covered. Missing feeds are excluded, not scored as zero.
Can be shown, without a risk score: Wind direction and speed, one-hour rainfall forecast, and elevation with sampled local relief. These do not establish exposure to a particular incident or protection at a building.
No verified postcode-level assessment: Military targeting, building structure and designated shelter availability. A postcode prefix cannot supply these details.

Full scoring method · Compare full postcodes · UK Emergency Alerts