Worst air pollution Nelson Caerphilly, today and tomorrow
Today (20 September): Air quality in Nelson Caerphilly is moderate. AQI and PM1 are moderate; PM2.5, PM10, and NO2 are fair; O3, SO2, CO, and HCHO are good. Pollution peaks around 11:00 PM (PM1: 44.1/100).
Tomorrow (21 September 2026): Air quality in Nelson Caerphilly is moderate. PM2.5 increases to moderate; NO2 increases to moderate; all other pollutants stay as today. Pollution peaks around 10:00 PM (PM1: 59.5/100). 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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The A470 sees the heaviest traffic, and that shows up clearly in local roadside monitoring. Nelson Caerphilly's air quality reflects its position within Caerphilly, with local traffic and the town's built-up core as the main contributors. Inland breezes from the surrounding countryside help ventilate the town centre, keeping air quality at moderate levels typical for the region.
Today - 20 September | Pollution peaks at 23:00
AQI:
Moderate
44.1/100
PM2.5 (fine particles):
Fair
28.4/100
PM10 (coarse particles):
Fair
23.8/100
NO2 (nitrogen dioxide):
Fair
37.4/100
O3 (ozone):
Good
18.0/100
SO2 (sulfur dioxide):
Good
5.6/100
CO (carbon monoxide):
Good
0.9/100
HCHO (formaldehyde):
Good
8.3/100
PM1 (ultrafine particles):
Moderate
44.1/100
Levels show the poorest local air quality during the day
Tomorrow - 21 September | Pollution peaks at 22:00
AQI:
Moderate
59.5/100
PM2.5 (fine particles):
Moderate
42.4/100
PM10 (coarse particles):
Fair
38.7/100
NO2 (nitrogen dioxide):
Moderate
57.6/100
O3 (ozone):
Good
18.6/100
SO2 (sulfur dioxide):
Good
10.9/100
CO (carbon monoxide):
Good
1.3/100
HCHO (formaldehyde):
Good
15.7/100
PM1 (ultrafine particles):
Moderate
59.5/100
Pollen forecast in Nelson Caerphilly
View pollen forecastFrequently Asked Questions
Is air quality bad in Nelson Caerphilly right now?
On 20 September 2026, overall air quality in Nelson Caerphilly is moderate. AQI is the main air quality indicator at 44.1/100. Pollution peaks around 11:00 PM (PM1: 44.1/100).
Will air quality be worse tomorrow in Nelson Caerphilly?
On 21 September 2026, air quality conditions in Nelson Caerphilly will be similar to today, with AQI forecast at moderate at 59.5/100. Pollution peaks around 10:00 PM (PM1: 59.5/100).
When is air pollution at its worst in Nelson Caerphilly?
Seasons make a real difference to air quality in Nelson Caerphilly, more than most people realise. The coldest months usually bring the worst readings, as heating and temperature inversions keep A470 emissions from dispersing normally. Summer sunshine can drive up ozone locally, though overall air generally moves and clears more freely than in winter. Spring and autumn usually sit somewhere in between, so it's really the extremes of the year worth watching.
Are air quality levels in Nelson Caerphilly 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 20:27 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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