: Check out the following pages that have been added and/or updated for Howth Tides, Air Traffic, Sea Area Forecasts, Marine Warnings & Sea Crossings Forecasts.

Air quality in Ireland

An air quality index (AQI) is a number used by government agencies to communicate to the public how polluted the air currently is or how polluted it is forecast to become. As the AQI increases, an increasingly large percentage of the population is likely to experience increasingly severe adverse health effects. Different countries have their own air quality indices, corresponding to different national air quality standards. For example,

  1. The Irish Environmental Protection Agency uses the Air Quality Index for Health (AQIH)
  2. The United States Environmental Protection Agency has developed their own Air Quality Index (AQI).

1.Using the Irish Air Quality Index for Health (AQIH)

What Is the Air Quality Index for Health (AQIH)?

The Environmental Protection Agency’s Air Quality Index for Health (AQIH) is a simple scale from 1 to 10 that shows the current air quality at the monitoring station nearest to you. It helps you understand how the air you’re breathing might affect your health — or your child’s.

Below is an example of AQIH in action.

Station: TNO2162-EPA - Coolock, Dublin 5
Rating 1 – Good
Pollutant Value (µg/m³)
PM2.5 1.83
PM10 2.45

Last updated: Sun 01 Feb 2026 23:31

Monitor Type: Osiris (Turnkey)

Location Coordinates: 53.390542, -6.202395

What do the Air Quality Index for Health (AQIH) categories, numbers and colours mean:
Good
1 2 3
Fair
4 5 6
Poor
7 8 9
Very Poor
10
  • 1 to 3: Good air quality — enjoy your day outdoors.
  • 4 to 6: Fair — sensitive individuals may want to limit prolonged outdoor activity.
  • 7 to 10: Poor to very poor — consider reducing outdoor exposure, especially if you have respiratory conditions.

Air quality data is courtesy of the Ireland Environmental Protection Agency (EPA). For more details see Airquality.ie.

2.Using the US Air Quality Index (AQI)

Example - Current Estimated Air Quality for Howth using the US Air Quality Index (AQI)

AQI ValueCategoryPollutants (µg/m³)
26GoodPM10: 22.5  PM2.5: 11.4  

Last reading taken at: Sun, 01 Feb 2026 23:00

Note: Based on modelled data from Open-Meteo, combining satellites and sensor networks. Values are estimates based on the regional air quality production of the Copernicus Atmosphere Monitoring Service (CAMS). The regional air quality models provide 4-day, daily forecasts of the main atmospheric pollutants concentrations, in the lowest layers of the atmosphere for the European domain and is courtesy of Open-Meteo.com.

Example - Details from St. Anne's Park monitoring station, Dublin 5, using the US Air Quality Index (AQI)

Air quality data is courtesy of the Ireland Environmental Protection Agency (EPA).

What Do the AQI categories, numbers and colours mean:

The Air Quality Indexes are based on a scale from 0 (good) to 500 (bad).

AQI Range Category Description
0–50GoodAir quality is considered healthy for everyone. Great for outdoor activities.
51–100ModerateAcceptable for most people, but those unusually sensitive to air pollution may feel mild effects.
101–150Unhealthy for Sensitive GroupsPeople with asthma, heart or lung conditions, older adults, and children should limit outdoor exertion.
151–200UnhealthyEveryone may start to feel effects. Sensitive groups could have more serious symptoms. Limit time outdoors if possible.
201–300Very UnhealthyHealth alerts in effect. Avoid outdoor activity. Public health risks increase for everyone.
301+HazardousEmergency conditions. Entire population is likely to be affected. Stay indoors with filtered air if available.

About Dominant Pollutants

  • NO2 (Nitrogen Dioxide): Mainly from vehicle engines and heating. Can irritate lungs, especially for children and people with asthma.
  • PM2.5 (Fine Particulate Matter): Tiny particles from burning (wood, fuels, industry). Can penetrate deep into lungs and affect heart and brain health.
  • PM10 (Coarse Particulate Matter): Dust and particles from roads, construction, agriculture. Can trigger breathing difficulties and allergies.
  • O3 (Ozone): Not the ‘good’ ozone up high, but ground-level ozone formed on sunny days. Can make breathing harder, especially during exercise.
  • SO2 (Sulphur Dioxide): From burning coal or oil. Can worsen asthma and irritate eyes, nose, and throat.
  • CO (Carbon Monoxide): From cars and poorly vented appliances. High levels reduce oxygen delivery to your body.

For more information about the pollutants included in the AQI scale, please refer to:

Realtime PurpleAir Sensor Air Quality

PurpleAir makes sensors that empower communities who collect hyper-local, real-time, air quality data and share it with the public.

A PurpleAir member in University College Dublin (UCD) Portmarnock has an air quality monitor and provides the data to PurpleAir. The live measurements from this station are shown below.

Air Quality in Dublin from PurpleAir using the US AQI

Updated: 29/08/2025 10:57
 
6 Good

0-50: Air quality is considered satisfactory, and air pollution poses little or no risk
 
Sensor 1

8
2 μg/m3

6
1.5 μg/m3

5
1.3 μg/m3

5
1.1 μg/m3

5
1.1 μg/m3

9
2.1 μg/m3
Real-Time
(page load)		 Short Term 30 Minutes 1 Hour 6 Hours 24 Hours
Sensor 2

8
2 μg/m3

6
1.5 μg/m3

6
1.4 μg/m3

5
1.2 μg/m3

5
1.2 μg/m3

10
2.3 μg/m3
Real-Time
(page load)		 Short Term 30 Minutes 1 Hour 6 Hours 24 Hours

These figures use the US Air Quality Index (AQI) which run from 0-500. The higher the AQI value, the greater the level of air pollution and the greater the health concern.

Other PurpleAir sensors around Dublin

The map below shows data from PurpleAir sensors around Dublin and displays the US Air Quality Index (AQI) with the choice of displaying the same data using the AQIH values. The map shows the location of the various sensors and their current readings. You can zoom in and out of this map.

Legend

PurpleAir Sensor Table

Only showing sensors that have reported readings this year

IDNamePM2.5 valueAQILast Updated

PurpleAir data courtesy of PurpleAir.