An interactive map of how many people reported being able to speak Irish in each county, across every census from 1851 to 2022.
Each county is shaded by the percentage of people aged 3 and over who told the census they could speak Irish. The colour scale is fixed across every year, so a shade always means the same percentage, which lets you watch the long decline and the more recent changes. Press Play animation on the map to step through the census years, or pick a year yourself, and click any county to see its exact figure and its trend over time.
The map covers all 32 counties: the 26 counties of the Republic and the six counties of Northern Ireland. Because the two parts of the island ran their censuses differently over time, some years are only available for part of the island. The methodology page explains exactly what is shown, what is estimated, and how comparable the figures are between distant years.
The project is open source. You can read the code, report an issue, or download the data on GitHub.