POSTCODE DISTRICT · WALES

Gwynedd LL55 postcode area

LL55 includes Caernarfon and nearby communities. Gwynedd combines towns, villages and open countryside, so its average describes a wider area.

DISTRICT REPORT SCOPE

Area evidence, not a full-postcode grade

The LL55 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 LL55: 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.

Gwynedd47 residents/km²UK council density percentile: 4/100

ONS mid-2025 population estimates · MYE5

Preparedness conclusion for LL55

Gwynedd is below the UK density average. The wider council figure can conceal differences between communities.

Gwynedd is 240 residents/km² below the UK average of 287 residents/km².

The council density combines towns, villages and open countryside. It cannot describe every LL55 settlement or distinguish the addresses on two different approaches to a village. A council-wide comparison is useful for context, but the location and extent of a Welsh warning still need to be checked directly.

Check Natural Resources Wales flood warnings

Local flood evidence for LL55

Recorded flooding

Natural Resources Wales records nine properties flooded in Caernarfon in January 2014 and later flooding associated with the Gwyrfai and Seiont in December 2015. These are Caernarfon-area events; LL55 also reaches settlements outside the town.

NRW north-west Wales flood risk management plan

Official warning area

The NRW Caernarfon Harbour tidal warning area is a named local service for part of the town. Check its boundary before applying it to an LL55 address inland or elsewhere in Gwynedd.

NRW Caernarfon Harbour warning area

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 LL55

If reaching your address involves travelling between communities, include that journey in your plan as well as the destination. Keep contact details that can be used if a normal route is unavailable, and check official local information before travelling during a disruption.

Cyngor Gwynedd publishes local flooding information and road updates. For an LL55 journey beyond Caernarfon, check the specific community and road named in any current notice.

Check a full LL55 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