Worst air pollution St Clears, today and tomorrow
Today (20 September): Air quality in St Clears is good. AQI, PM2.5, PM10, NO2, O3, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 10:00 AM (PM10: 19.9/100).
Tomorrow (21 September 2026): Air quality in St Clears is fair. AQI worsens to fair; PM2.5 increases to fair; PM10 increases to fair; NO2 increases to fair; PM1 increases to fair; all other pollutants stay as today. Pollution peaks around 9:00 PM (NO2: 36.0/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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Like much of Carmarthenshire, St Clears's air quality is shaped less by industry these days and more by everyday road traffic. Light prevailing breezes offer a degree of natural ventilation, keeping pollution broadly in line with comparable UK towns. The A470 generates consistent traffic-related NO₂ and PM2.5, particularly during peak commuting hours.
Today - 20 September | Pollution peaks at 10:00
AQI:
Good
19.9/100
PM2.5 (fine particles):
Good
16.4/100
PM10 (coarse particles):
Good
19.9/100
NO2 (nitrogen dioxide):
Good
13.9/100
O3 (ozone):
Good
15.6/100
SO2 (sulfur dioxide):
Good
2.1/100
CO (carbon monoxide):
Good
0.8/100
HCHO (formaldehyde):
Good
2.5/100
PM1 (ultrafine particles):
Good
10.9/100
Levels show the poorest local air quality during the day
Tomorrow - 21 September | Pollution peaks at 21:00
AQI:
Fair
36.0/100
PM2.5 (fine particles):
Fair
32.7/100
PM10 (coarse particles):
Fair
27.0/100
NO2 (nitrogen dioxide):
Fair
36.0/100
O3 (ozone):
Good
16.8/100
SO2 (sulfur dioxide):
Good
5.3/100
CO (carbon monoxide):
Good
1.0/100
HCHO (formaldehyde):
Good
5.7/100
PM1 (ultrafine particles):
Fair
28.3/100
Pollen forecast in St Clears
View pollen forecastFrequently Asked Questions
Is air quality bad in St Clears right now?
On 20 September 2026, overall air quality in St Clears is good. AQI is the main air quality indicator at 19.9/100. Pollution peaks around 10:00 AM (PM10: 19.9/100).
Will air quality be worse tomorrow in St Clears?
On 21 September 2026, air quality conditions in St Clears will be worse than today, with AQI forecast at fair at 36.0/100. Pollution peaks around 9:00 PM (NO2: 36.0/100).
When is air pollution at its worst in St Clears?
You can roughly predict St Clears's air quality just by knowing the time of year. Summer brings a different issue — stronger sunlight can push up ozone levels on hot, sunny days, even though traffic pollution itself often disperses more easily. Through the colder months, readings near the A470 often rise, since chimney smoke and stagnant air stop pollutants clearing away. The shoulder seasons generally bring the mildest readings of the year.
Are air quality levels in St Clears based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
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Data provided by Airmine — Last update: 20 September 2026 at 14:33 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
Some text on this page may be generated or summarised using artificial intelligence (AI). Wherever possible, AI-generated content is enriched with Airmine's proprietary data to improve its accuracy and relevance. However, AI-generated content may still contain errors, omissions, or inaccuracies.
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