Photo: Matthew Hatton · CC BY-SA 2.0More terraced houses than 93% of UK towns: 39% of households
21% of households live in a detached house across England’s towns, against 16% in Seaham. Here, 97% of residents describe themselves as White British. Fewer shared households of unrelated adults than in 86% of UK towns: 1.7%. In 2021, the Census found 21,660 residents in the town, living in 9,607 households.
What the Census says about Seaham’s people
Fewer people than in 2011
ONS mid-year estimates put Seaham at 22,700 in 2011 and 22,600 in 2024, down 0%, against 10% for England: slower growth than in 86% of UK towns. Since 2011 ↓
Written from the data on this page: ONS Census 2021 (output areas summed to the 2022 built-up area) and ONS mid-year population estimates.
Seaham’s population moved ±0% on 2011, less than in 86% of UK towns
ONS mid-year estimates, each year indexed to mid-2011 = 100. Seaham’s figure is the small areas (2021 LSOAs) that make up the town.
People, mid-2011 = 100
Change by age, 2011 to 2024
About 22,700 people in 2011; 22,600 in 2024.
The 65 and over age group moved most (+22%); the 16 to 29 group moved least (−16%).
10% of residents are aged 15 to 24, a share 65% of UK towns don’t reach
Share of residents in each five-year age band, Census 2021.
Half of Seaham’s residents are under 43.6, younger than in 57% of UK towns. The biggest five-year age group is 55–59, with 7.7% of residents. As a reference point, 12% of residents are aged 15 to 24 across England’s towns. Compared with 18% across England’s towns, 20% of residents are 65 or over here.
Median age of UK towns of 2,500+
■ Seaham, 43.6. The typical town is 44.4.
Broad ages · share of residents
Women and men · all residents
51% women, 49% men
About 94 men for every 100 women. Across England, 51% of residents are women.
A smaller share of residents who moved in within the year than 86% of UK towns: 6.9%
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%.
Managerial and professional jobs take in 23% of adults here, routine and semi-routine work 31% (England’s towns: 33% and 24%). Residents who moved in within the year: 11% across England’s towns, for comparison. The census found that 5.3% of adults are full-time students in Seaham.
The Census was taken on 21 March 2021, in term time, so students were counted at their term addresses.
More people live alone than in 72% of UK towns: 33% of households
Household make-up at the 2021 Census. Each square is 1% of households.
Against County Durham’s towns and England’s towns
People per household
England’s towns.
In Seaham the average household is 2.2 people, beside 2.4 across England’s towns. The usual figure: 30% of households are one person living alone across England’s towns. Across Seaham, 28% of households have dependent children.
Above 93% of UK towns: 28% of households have no car or van
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
Where nearly a quarter of households live in a flat or apartment across England’s towns, Seaham has 7.9%. The comparison figure for households without a car or van is 24% across England’s towns.
2.9% born outside the UK, fewer than in 93% of UK towns
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 25%
When those born abroad arrived
Main language · residents aged 3 and over
The share of residents whose main language is English tops 77% of UK towns: 99%. By way of comparison, 18% of residents were born outside the UK across England’s towns. Residents born abroad were most often born in EU countries (1.5%), then in the Middle East and Asia (0.8%).
Residents who describe themselves as Christian: 58%, a higher share than 90% of UK towns
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 Seaham · County Durham’s towns 93% · England’s towns 73%.
Religion · all residents
Other than White British, most residents describe themselves as Other White (1.3%), Mixed or multiple (0.6%) and Indian (0.3%). Compared with other places, residents with no religion are scarce here: 36%, fewer than in nearly four fifths of UK towns. The benchmark for residents who describe themselves as Christian across England’s towns: 46%.
Unpaid carers: 11%, a higher share than 89% 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
Set against 39% across England’s towns, 36% of adults have never married or formed a civil partnership in Seaham. At 44%, the share of married adults and civil partners is lower than in just over three quarters of UK towns. Across England’s towns, the share of unpaid carers is 8.7%. For 848 residents, unpaid care runs to 50 hours or more a week.
Degree-level qualifications reach 22% of adults
Highest qualification, residents 16 and over, Census 2021.
Highest qualification · residents 16 and over
Degree-level qualifications are held by 22% of adults in Seaham (England’s towns: 34%), and no qualification by 25% (England’s towns: 18%).
From a median age of 39 in Murton North & Parkside to 46 in Seaham Northlea & Westlea
The town’s 3 neighbourhoods (ONS middle-layer areas with 500+ residents inside it, named by the House of Commons Library), youngest first. Census 2021.
Seaham Northlea & Westlea is the oldest area, with 21% aged 65 or over; Murton North & Parkside the youngest (median age 39). Families with children are most common in Murton North & Parkside (32% of households).
Among 289 UK towns of 15,000 to 29,000 people, the 143rd oldest
Median age, Census 2021. Hover a dot for its students and residents born abroad; click for its page.
Ages run from 26.4 in Bangor to 57.2 in South Hayling. Nearest to Seaham in age: Golborne (43.5), Gorleston-on-Sea (43.5), Crowthorne (43.6) and Swinton (43.7).
Among its 7 nearest neighbours, 3 are older than Seaham
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 |
|---|---|---|---|---|---|
| Seaham | 21,660 | — | 43.6 | 20% | 28% |
| Murton | 7,239 | 1.9 mi | 42.7 | 20% | 27% |
| South Hetton | 2,877 | 3.4 mi | 42.3 | 17% | 28% |
| Easington | 6,968 | 3.6 mi | 44.5 | 22% | 25% |
| Easington Lane | 4,170 | 3.8 mi | 35.8 | 13% | 33% |
| Hetton-le-Hole | 8,968 | 4.1 mi | 47.3 | 25% | 24% |
| Haswell | 1,185 | 4.5 mi | 43.9 | 19% | 26% |
| Houghton-le-Spring | 12,552 | 4.8 mi | 42.8 | 22% | 28% |
Health, work and homes have their own pages
What this data can and can’t tell you
- The Census was taken in a lockdown, in term time. 21 March 2021 fell in term time, and students were asked to give their term-time address, so most were counted where they study. Some may have been living with family that day.
- “County Durham’s towns” and “England’s towns” mean their built-up areas. Census comparisons pool every built-up area in County Durham (or England), summed the same way as Seaham’s figures, so households in open countryside are left out. The population trend compares with the whole county and nation.
- Estimates since 2021 are modelled. The ONS builds mid-year estimates from the Census, births, deaths and migration records. Seaham’s trend uses the small areas (2021 LSOAs) with most of their people inside it: 22,267 people in 2021, against 21,660 in the built-up area.
- 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 Seaham’s residents
What is the population of Seaham?
The 2021 Census counted 21,660 people in Seaham’s built-up area. The ONS estimates the same small areas held 22,600 people in mid-2024, about as many as in 2011.
What is the average age in Seaham?
The median age was 43.6 at the 2021 Census, younger than 57% of UK towns. 10% of residents were 15 to 24 and 20% were 65 or over.
How diverse is Seaham?
97% of residents described themselves as White British in 2021, against 73% across England’s towns and 93% across County Durham’s towns. 2.9% were born outside the UK.
What religion are people in Seaham?
36% said they had no religion and 58% that they were Christian at the 2021 Census; 0.6% were Muslim and 4.5% didn’t answer.
Is Seaham good for families?
28% of households had dependent children in 2021, against 29% across England’s towns. Families are most common in Murton North & Parkside (32% of households). Schools are on Seaham’s schools page.
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) · ONS mid-year population estimates for 2021 LSOAs, mid-2011 to mid-2024 · House of Commons Library MSOA names. 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.