Each year, the Office for National Statistics (ONS) publishes ‘mid-year estimates’ of populations at national and local authority levels. These are based on Census data, updated to allow for subsequent birth rates, death rates and estimated migration patterns using sources such as regional birth and mortality records, the International Passenger Survey (IPS) and National Asylum Support Service for international migration, Labour Force Survey, Higher Education Statistics Agency (HESA) and the GP Patient Register database (PRDB, for internal migration).
Key Facts for Somerset
In the year to 30th June 2017, Somerset’s population is estimated to have increased by 3,749 to 555,195.
Amongst the 65-74 age group, the annual rate of growth was an estimated 2.4%, the rate for England being 1.5%. This partly reflects the attraction of Somerset as a retirement destination, and also the post-war baby-boom generation reaching retirement age.
All Somerset districts experienced an increase in population.
West Somerset has the highest number of total moves in and out per head of population of any of the five Somerset districts (129 per 1,000).
There were more deaths than births in 2016/17, although in Sedgemoor the reverse was true.
In 1991, the largest five-year age group was 40-44 but in 2017 it was the 50-54 age group.
91% of the overall growth in Somerset is explained by internal migration. In the year to June 2017, 3,404 more people moved into Somerset from elsewhere in the UK than moved out.
Somerset continues to see a net ‘inflow’ across most age groups, but with a key exception being the 18-20 age group. Amongst 18-20 year-olds, 2,292 more moved away than moved in, most commonly to the university cities of Cardiff, Plymouth, Bath and Bristol.
The annual net increase in international migrants was 747.
Somerset's population is projected to continue rising by at least 3,000 a year for the next decade, reaching over 600,000 by 2031. The increase will then get gradually smaller, until it is just above 2,000 a year in 2041 when Somerset's population is projected to be just under 625,000.
The number of people aged 75 or older is projected to almost double by 2041.
The 2017 mid-year estimates were published in June 2018 and indicate that the population of Somerset has risen by 3,749 to 555,195. The total is broken down by age group and district in the table below.
The charts below illustrate how the populations of Somerset and the five Districts have changed markedly in the past 25 years, not only in size, but also in their age and gender profile. On the charts, you can see the actual numbers by hovering the cursor over the appropriate line or bar.
What if Somerset Districts were sized based on their population? The map below shows what the County might look like if the size of the Districts was proportional to their population.
Components of population change
For the third successive year, there was a negative ‘natural’ change in population in Somerset, with deaths exceeding births (see table below).
Components of Population Change in Somerset, year ending June 2017
Births - Deaths
As usual, the majority (over 90%) of the estimated year-on-year increase in Somerset’s population is due to internal migration (i.e. migration from other parts of the UK), with an increase of 3,404 people in the year to June 2017. By comparison, net international inflow (that is, people from outside the UK) also saw an increase of 747 people.
Somerset has a population density of 161 people per square kilometre (sq km). Each of the five districts in the county has a population density below that of the UK average (272 per sq. km). West Somerset's population density of 48 per sq km is the seventh lowest of any local authority in England.
Local Area Population Estimates
In October 2018, the ONS published population estimates for June 2017 by age group at smaller geographies, such as District, Electoral Ward and Lower-layer Super Output Area (LSOA). Headlines include:-
The mean population of the 138 wards in Somerset is 4,023.
Population sizes range from 9,586 in North Petherton ward to 1,150 in Greater Exmoor ward.
Since the 2011 Census, 98 wards are estimated to have gained population, while 40 are estimated to have seen a decrease.
Since 2011, the largest estimated increases have been in North Petherton ward (2,431 residents, a rise of 34%) and West Monkton ward (1,954, 45%).
Since 2011, the largest estimated falls have occurred in Minehead Central ward (141, 3%) and Yeovil West ward (307, 4%).
Based on Lower level Super Output Areas (LSOAs) in 2016, the area with the highest population density is Taunton Rowbarton South (9,626 per sq km), and the lowest is Exford (just 8 per sq km).
For detailed figures for Wards and LSOAs in Somerset, please click here.
For data on all geographies across England and Wales, please go to the ONS website.
In May 2018, the ONS released new population estimates projected to the year 2041 by single year of age and local authority, based on the 2016 mid-year estimates. The Somerset population is projected to rise by around 73,400 (12%) over the twenty-five year period, to 624,800 (see chart below).
Projected growth amongst the 65+ age group is even greater, at around 35%, and the number of people aged 75 or more is projected to close to double over the period, to almost 117,500.
The under-16 population is projected to increase by 3% by 2041, with the great majority of this increase in the next seven years. The ‘working age’ population is projected to witness a slight (-0.5%) decline over the next twenty-five years, with most of the fall coming beyond 2026.
Between 2016 and 2041, Sedgemoor and Taunton Deane are projected to experience the highest growths in percentage terms, 16% and 14%, respectively. The projected trend totals for selected years are shown below.
The 'population pyramid' below highlights the ageing profile of Somerset residents.
In 1961 (see the light coloured lines), the post-war baby boom led to a 'spike' in teenagers.
In 2013 (bars), the most populous age groups are those in their 40s, 50s and 60s
By 2033 (darker lines), there is projected to be a bulge in the 70-79 age groups, with almost as many in their 80s as in their 20s
Comparison of the population in 2013, and local projections, show how most of Somerset, including almost all rural areas, is likely to have at least 25% of the population over 65 by 2033 (see maps below)
Proportion of population aged 65 and over, 2013
Proportion of population aged 65 and over, 2033
Note that these are trend-based projections, which means assumptions for future levels of births, deaths and migration are based on observed levels mainly over the previous five years. They show what the population will be if recent trends continue and don't take into account any policy changes that have not yet occurred (e.g Hinkley Point construction), nor those that have not yet had an impact on observed trends.
Note, too, that as the period since the latest Census increases, so will the likely inaccuracy of population estimates. Furthermore migration data, particularly international, are relatively unreliable at local levels because IPS samples are very small at small geography levels, requiring combining of areas and time periods.
For the latest information about birth rates in Somerset, population projections for children and young people and school roll forecasts, please go to the pages below.
Looking ahead to 2021 and beyond, the ONS has established a Census Transformation Programme. Its aim is to make the best use of all available data in England and Wales to enhance the provision of population statistics. It will:-
provide an online census in 2021,
seek to increase the use of administrative data to enhance population statistics,
form plans for the provision of population statistics after 2021.
For example, the ONS have carried out extensive research into the use of administrative data (such as those held by the DWP, NHS Patient Registers and School Census) to generate unofficial estimates of local population sizes.
In November 2016, this methodology provided retrospective estimates for Somerset which are higher than the 2011 Census and 2015 mid-year estimates. More work is being done to understand the differences. However, there is evidence that higher estimates are often found in areas, such as Somerset, with relatively high numbers of seasonal workers, residential schools and people contacting administrative services (eg health and social care).