Worst air pollution Trafalgar Square - London, today and tomorrow
Today (9 August): Air quality in Trafalgar Square is poor. AQI and O3 are poor; PM2.5, NO2, and PM1 are fair; PM10, SO2, CO, and HCHO are good. Pollution peaks around 3:00 PM (O3: 60.4/100).
Tomorrow (10 August 2026): Air quality in Trafalgar Square is fair. AQI improves to fair; PM2.5 decreases to good; NO2 decreases to good; O3 decreases to fair; PM1 decreases to good; all other pollutants stay as today. Pollution peaks around 5:00 PM (O3: 28.2/100). 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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Trafalgar Square's position in London, City of means air quality is mostly determined by local road traffic and the compact scale of the centre. Cooler northerly winds do most of the work keeping things in check, more so than any local policy or infrastructure change. Emissions along the M20 represent the town's main traffic-related pollution source.
Today - 9 August | Pollution peaks at 15:00
AQI:
Poor
60.4/100
PM2.5 (fine particles):
Fair
24.5/100
PM10 (coarse particles):
Good
6.7/100
NO2 (nitrogen dioxide):
Fair
34.5/100
O3 (ozone):
Poor
60.4/100
SO2 (sulfur dioxide):
Good
5.8/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
12.8/100
PM1 (ultrafine particles):
Fair
31.0/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 17:00
AQI:
Fair
28.2/100
PM2.5 (fine particles):
Good
6.4/100
PM10 (coarse particles):
Good
2.3/100
NO2 (nitrogen dioxide):
Good
6.5/100
O3 (ozone):
Fair
28.2/100
SO2 (sulfur dioxide):
Good
1.2/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
3.8/100
PM1 (ultrafine particles):
Good
4.7/100
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Frequently Asked Questions
Is air quality bad in Trafalgar Square right now?
On 9 August 2026, overall air quality in Trafalgar Square is poor. AQI is the main air quality indicator at 60.4/100. Pollution peaks around 3:00 PM (O3: 60.4/100).
Will air quality be worse tomorrow in Trafalgar Square?
On 10 August 2026, air quality conditions in Trafalgar Square will be better than today, with AQI forecast at fair at 28.2/100. Pollution peaks around 5:00 PM (O3: 28.2/100).
When is air pollution at its worst in Trafalgar Square?
Spring and autumn usually sit somewhere in between, so it's really the extremes of the year worth watching. If you're tracking air quality in Trafalgar Square, expect it to move around quite a bit through the year. The coldest months usually bring the worst readings, as heating and temperature inversions keep M20 emissions from dispersing normally. Warmer months swap one problem for another — less smoke and heating pollution, but more ozone on the sunniest days.
Are air quality levels in Trafalgar Square 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: 9 August 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.
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