Every place in Wales, one map.

Wales publishes a lot about itself. It’s just scattered.

The Office for National Statistics, the Welsh Government, NHS Wales, the police and HM Land Registry each publish figures on their own websites, in their own formats, on their own timetables. Seeing the full picture for one town meant a dozen downloads and a lot of patience.

So we put it in one place. Pick an area, whether that’s all of Wales, a health board, a council or a single neighbourhood, and see what’s known about it on one map.

Every figure is exactly what its publisher printed

We don’t estimate, fill gaps or adjust. If a publisher has nothing for an area, you’ll see a gap, not a guess. When we do our own arithmetic, such as a percentage change in a digest article, we label it as ours.

Each figure also carries a paper trail: where we found it, how we loaded it, when we last re-checked it against the source, and whether the page shows it correctly.

How we check every figure ↓

Ten topics, four levels

Hundreds of measures, from housing and health to the Welsh language. More arrive as each new source passes our checks.

How we check every figure

What we calculate

Almost nothing. We don’t turn counts into rates or per-person figures unless the publisher did. We don’t join a series across a change in how it was counted. And we don’t rank a measure built for one purpose against a different measure from somewhere else.

We do our own sums in three places, and each is labelled as ours:

• A national or regional total, added up from its councils’ own figures for the same period.
• A percentage change in a digest article, worked out from two published numbers that we print alongside it.
• A projection in a deep dive, kept in its own panel and marked as not a statistic.

The paper trail

Under every figure is a thin line with four marks. Each mark is one check we ran on that number.

1. 01

   Found in source

   We record exactly which dataset and which measure the publisher printed the figure in.

2. 02

   Loaded

   The file passed our checks on the way in, and was loaded whole or not at all.

3. 03

   Re-checked

   We fetch the publisher’s file again and compare every value with what we hold.

4. 04

   Shown correctly

   We check the page shows the right row and the right period, not just the right table.

A complete line means all four checks passed. A gap means one hasn’t run yet, and we say what that means for the figure. If a check ran and failed, we print that next to the number, so you never have to go looking.

Fair ranks

We only rank an area against others at the same level in Wales: a council against the other 21 councils, a neighbourhood against the other 1,916 neighbourhoods.

We only give a percentile where there are at least 100 areas to compare, which means neighbourhoods and middle areas. With 22 councils or 7 health boards, a percentile would sound more precise than it is, so a council reads simply as 4th of 22.

Census 2011 and 2021

Wales’s 22 councils covered the same ground in 2011 and 2021, so for councils we show both censuses side by side.

Neighbourhoods are different. Between the two censuses they were redrawn, going from 1,909 to 1,917, with some split and others merged. Fitting 2011 figures onto today’s boundaries would mean estimating numbers nobody measured, so we don’t. Neighbourhood and middle-area census figures start in 2021.

Where both censuses appear on one chart, the line breaks between them and the reason is cited. Some census questions also changed wording between 2011 and 2021; we follow the ONS’s own comparability guidance and only pair the questions it rates as comparable.

Citing a figure

Credit the publisher as the source, and datamap.cymru as where you found it. Each measure’s page names the exact table and when we last checked it.

Licences and credits

We republish public data; we don’t own it. Most publishers use the Open Government Licence v3.0. Where one asks for its own credit line, we print it word for word:

See the Open Government Licence v3.0. Each measure’s page names its publisher.

The background map uses OpenStreetMap data through OpenFreeMap, under the Open Database Licence, and is credited on the map itself.

Get in touch

Spotted a figure that doesn’t match the publisher’s? Email datamapwls@gmail.com with the page link and the publisher’s number. We’ll check it, and if we’re wrong, we’ll fix it and note the change.

Ideas for new sources are welcome at the same address.

An independent project, not part of, funded by or endorsed by the Welsh Government or any public body. Built with SvelteKit, MapLibre GL JS, FastAPI and SQLite.