Worst air pollution Caernarfon, today and tomorrow
Today (16 July): Air quality in Caernarfon is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 3:00 PM (O3: 28.4/100).
Tomorrow (17 July 2026): Air quality in Caernarfon is fair. All pollutants stay as today. Pollution peaks around 2:00 PM (O3: 29.3/100). 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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Caernarfon's air quality reflects its position within Gwynedd, with local traffic and the town's built-up core as the main contributors. The A483 sees the heaviest traffic, and that shows up clearly in local roadside monitoring. Light prevailing breezes offer a degree of natural ventilation, keeping pollution broadly in line with comparable UK towns.
Today - 16 July | Pollution peaks at 15:00
AQI:
Fair
28.4/100
PM2.5 (fine particles):
Good
11.0/100
PM10 (coarse particles):
Good
3.9/100
NO2 (nitrogen dioxide):
Good
9.6/100
O3 (ozone):
Fair
28.4/100
SO2 (sulfur dioxide):
Good
2.3/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
1.8/100
PM1 (ultrafine particles):
Good
8.6/100
Levels show the poorest local air quality during the day
Tomorrow - 17 July | Pollution peaks at 14:00
AQI:
Fair
29.3/100
PM2.5 (fine particles):
Good
14.6/100
PM10 (coarse particles):
Good
5.2/100
NO2 (nitrogen dioxide):
Good
12.9/100
O3 (ozone):
Fair
29.3/100
SO2 (sulfur dioxide):
Good
3.7/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
2.1/100
PM1 (ultrafine particles):
Good
11.7/100
Pollen forecast in Caernarfon
View pollen forecastFrequently Asked Questions
Is air quality bad in Caernarfon right now?
On 16 July 2026, overall air quality in Caernarfon is fair. AQI is the main air quality indicator at 28.4/100. Pollution peaks around 3:00 PM (O3: 28.4/100).
Will air quality be worse tomorrow in Caernarfon?
On 17 July 2026, air quality conditions in Caernarfon will be similar to today, with AQI forecast at fair at 29.3/100. Pollution peaks around 2:00 PM (O3: 29.3/100).
When is air pollution at its worst in Caernarfon?
For much of spring and autumn, things settle into a fairly unremarkable middle ground. Air quality in Caernarfon isn't the same all year round — it really shifts with the seasons. Once the heating goes on and the air turns still, pollution from the A483 and nearby chimneys tends to build up rather than clear. Warmer months swap one problem for another — less smoke and heating pollution, but more ozone on the sunniest days.
Are air quality levels in Caernarfon 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.
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Data provided by Airmine — Last update: 16 July 2026 at 10:33 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.
For long term forecasts and maps, see the Airmine app