Photo: Ian Greig · CC BY-SA 2.0Half of Trearddur is over 58.9, older than 99% of UK towns
Just over three in five adults are married or in a civil partnership, against 43% across Wales’s towns. The 2021 Census counted 932 residents in 445 households. Census figures put households in detached houses at 80% in Trearddur. On households without a car or van, Trearddur sits lower than 95% of UK towns: 7.2%.
In Trearddur, 38% of residents are 65 or over, more than in 99% of UK towns
Share of residents in each five-year age band, Census 2021.
70–74 is the most common age band: 12% of residents, 2.1 times the share across Wales’s towns. Typically, 21% of residents are 65 or over across Wales’s towns. Locally, 7.7% of residents are aged 15 to 24.
Broad ages · share of residents
Women and men · all residents
52% women, 48% men
About 91 men for every 100 women. Across Wales, 51% of residents are women. Women live longer than men, so towns with many older residents have more women.
3.4% of adults are full-time students, below 96% of UK towns
What adults did at the 2021 Census (the ONS’s NS-SEC classes), and where residents lived a year earlier.
Adults by occupation class · residents 16 and over
Address a year before the Census
Residents who lived somewhere else a year earlier. The bar runs to 25%.
Nearly one in ten residents lived at another address a year earlier (Wales’s towns: 9.1%). The usual figure: 8% of adults are full-time students across Wales’s towns.
Only 13% of households have dependent children in Trearddur
Household make-up at the 2021 Census. Each square is 1% of households.
Against Gwynedd’s towns and Wales’s towns
People per household
Wales’s towns.
1.8% of households are unrelated adults living together, against 3.1% across Wales’s towns. Fewer one-person households than in 59% of UK towns: 29%. Across the comparison, 27% of households have dependent children across Wales’s towns. Each household has 2.1 people on average.
Households in terraced houses: 5.2%, a lower share than 98% of UK towns
Accommodation type and cars or vans per household, Census 2021. Owning and renting are on Cost of living.
Type of home
Cars or vans · share of households
Households in flats: 7.2% here and 14% across Wales’s towns. Across Wales’s towns, 29% of households live in a terraced house.
A larger share of residents whose main language is English than 98% of UK towns: 99%
Country of birth, year of arrival and main language, Census 2021.
Born outside the UK, by region · share of all residents; the bar runs to 10%
Main language · residents aged 3 and over
Where 7.4% of residents were born outside the UK across Wales’s towns, Trearddur has 5.1%. The benchmark for residents whose main language is English across Wales’s towns: 96%. Residents born abroad were most often born in EU countries (2.7%), then in the Middle East and Asia (1%).
In Trearddur, Welsh is a language for 34% of residents
Welsh language skills, residents aged 3 and over, Census 2021.
Welsh language skills · residents aged 3 and over
Across Welsh towns, 16% of residents can speak Welsh; here 315 people, 34% of those aged 3 and over, said they can: more than in 84% of Welsh towns. Top of Gwynedd: Caernarfon, at 82%.
More residents who describe themselves as Christian than 97% of UK towns: 63%
How residents described themselves at the 2021 Census. Lines join the lowest and highest of the three figures.
Ethnic groups other than White British · all residents
White British, not charted: 97% of Trearddur · Gwynedd’s towns 93% · Wales’s towns 90%.
Religion · all residents
In Trearddur, 31% of residents said they have no religion, beside 47% across Wales’s towns. Measured more widely, 43% of residents describe themselves as Christian across Wales’s towns. Behind White British, the largest groups are Other White (1.6%), Mixed or multiple (1.3%) and Indian (0.1%). On residents who describe themselves as White British, Trearddur sits higher than 93% of UK towns: 97%.
Adults who have never married: 20%, a lower share than 99% of UK towns
Legal partnership status (residents 16 and over) and unpaid care (residents 5 and over), Census 2021.
Partnership status · residents 16 and over
Unpaid care given · share of residents 5 and over
11% of residents give unpaid care (Wales’s towns: 10%). The wider picture: 38% of adults have never married or formed a civil partnership across Wales’s towns. Unpaid carers giving 50 hours or more a week: 31.
Adults with a degree-level qualification: 37%
Highest qualification, residents 16 and over, Census 2021.
Highest qualification · residents 16 and over
Trearddur’s adults: 37% with a degree-level qualification and 14% with none, against 31% and 20% across Wales’s towns.
No nearby town is as old as Trearddur
Nearby built-up areas coloured by median age, Census 2021. Tap a town for its page.
| Town | People | Away | Median age | 65+ | Homes with children |
|---|---|---|---|---|---|
| Trearddur | 932 | — | 58.9 | 38% | 13% |
| Holyhead | 11,753 | 1.6 mi | 39.4 | 18% | 29% |
| Valley | 2,003 | 2.4 mi | 51.2 | 29% | 23% |
| Bodedern | 1,193 | 5 mi | 41.2 | 20% | 29% |
| Llanerchymedd | 1,155 | 10.6 mi | 44.3 | 21% | 30% |
| Cemaes | 1,023 | 11.1 mi | 57.2 | 37% | 18% |
Health, work and homes have their own pages
What this data can and can’t tell you
- “Gwynedd’s towns” and “Wales’s towns” mean their built-up areas. Census comparisons pool every built-up area in Gwynedd (or Wales), summed the same way as Trearddur’s figures, so households in open countryside are left out.
- Small counts are blurred. The ONS adds small random changes to Census counts to protect privacy, so the same total differs a little between tables, and the shares of a small town can move by a point or two.
Questions about Trearddur’s residents
What is the population of Trearddur?
The 2021 Census counted 932 people in Trearddur’s built-up area.
What is the average age in Trearddur?
The median age was 58.9 at the 2021 Census. 7.7% of residents were 15 to 24 and 38% were 65 or over.
How diverse is Trearddur?
97% of residents described themselves as White British in 2021, against 90% across Wales’s towns and 93% across Gwynedd’s towns. 5.1% were born outside the UK.
What religion are people in Trearddur?
31% said they had no religion and 63% that they were Christian at the 2021 Census; 0.5% were Muslim and 5.4% didn’t answer.
Is Trearddur good for families?
13% of households had dependent children in 2021, against 27% across Wales’s towns. Schools are on Trearddur’s schools page.
How many people speak Welsh in Trearddur?
315 residents aged 3 and over, 34%, said they can speak Welsh at the 2021 Census, against 16% across Welsh towns.
Sources: ONS Census 2021, output areas summed to the ONS 2022 built-up area (TS002, TS003, TS004, TS007A, TS008, TS015, TS017, TS019, TS021, TS029, TS030, TS039, TS044, TS045, TS062, TS067, TS032). All under the Open Government Licence v3.0.
Contains public sector information licensed under the Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right 2026. Contains OS data © Crown copyright and database right 2026 (ONS boundaries). Northern Ireland: Source: NISRA; contains Land & Property Services data and Ordnance Survey of Northern Ireland information, © Crown copyright, licensed under the Open Government Licence v3.0. Scotland: contains National Records of Scotland data, Registers of Scotland data and SEPA data, © Crown copyright / © SEPA 2025, licensed under the Open Government Licence v3.0.