SmogRank / World / Europe / Ireland / Leinster

Most polluted cities in Leinster, Ireland

10 measured cities, this year; 10 above the WHO annual guideline. Worst: Enniscorthy at 8.6 µg/m³, #1,527 in the world.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

Leinster: 10 measured citiesMunster: 3 measured citiesConnacht#9 Naas: 6.1 µg/m³#10 Greystones: 6.1 µg/m³#8 Carlow: 6.2 µg/m³#7 Leixlip: 6.4 µg/m³#6 Drogheda: 6.5 µg/m³#5 Dublin: 6.8 µg/m³#4 Longford: 6.9 µg/m³#3 Athlone: 7.5 µg/m³#2 Wexford: 7.9 µg/m³#1 Enniscorthy: 8.6 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.
← Wexford 1% 0.75%0
Every measured city in Leinster, Ireland, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Wexfordlast full day 3 Oct 1%
  2. 2Enniscorthylast full day 3 Oct 0%
  3. 3Athlonelast full day 3 Oct 0%
  4. 4Longfordlast full day 3 Oct 0%
  5. 5Dublinlast full day 3 Oct 0%
  6. 6Droghedalast full day 3 Oct 0%
  7. 7Leixliplast full day 3 Oct 0%
  8. 8Carlowlast full day 3 Oct 0%
  9. 9Naaslast full day 3 Oct 0%
  10. 9Greystoneslast full day 3 Oct 0%
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Estimated: cities without a monitor

Leinster cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City7-day estimateBand
Droichead Nua≈ 4 µg/m³Good
An Muileann gCearr≈ 4 µg/m³Good
Sandyford≈ 5 µg/m³Good
Balbriggan≈ 6 µg/m³Good
Kilkenny≈ 5 µg/m³Good
Celbridge≈ 5 µg/m³Good
Finglas≈ 5 µg/m³Good
Rathfarnham≈ 5 µg/m³Good
Maynooth≈ 5 µg/m³Good
Malahide≈ 6 µg/m³Good
Tullamore≈ 4 µg/m³Good
Lucan≈ 5 µg/m³Good

Bad-air episodes in Leinster

Times when many cities around here had PM2.5 at twice their usual or more on the same days.

Use this board

SmogRank, most polluted cities in Leinster, Ireland, PM2.5, this year to 6 Oct 2026, 22:00 UTC, smogrank.com/ie/region/leinster?w=year.

Download top 10 (PNG)

You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Updated 2026-10-06 22:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.