Blackpool has the oldest average age per resident for large towns and cities in the UK.
Blackpool has the oldest population of any UK major location, with an average age of 43.2.
The place with the youngest population is Slough, with an average age of 33.9 and only one in 10 people aged 65 and over.
The Centre for Cities looked at built-up urban areas with 135,000 or more people, rather than just officially recognised cities.
Other areas with higher average ages include Worthing (43), Bournemouth (42.8) and Southend (42.2) - apparently reflecting the pull of the seaside for people who have finished their working lives.
At 38, the average city dweller is younger, the survey said.
Cities are home to 62 per cent of people aged 18-34, but only 46 per cenr of those aged 65 and over.
Despite this, the populations of most UK cities are growing older, raising big questions about what that means for their development, and for meeting the future needs of residents.
Over the past 20 years, younger people have increasingly chosen to live in urban areas, while the share of older residents in cities has fallen.
In 1996, 58 per cent of people aged 18-34 lived in cities, but this had risen to 62 per cent by 2016.
In contrast, the share of people aged 65 or older in cities fell from 51 per cent to 46 per cent during this period.
Preston’s figure was 39.9, Blackburn was 36.9 while Wigan was 40.6.