Air Quality near Harlesden (AQI 165)
Right now
The most recent data we hold from OpenAQ and the agency that runs each station arrived 2 hours ago.
Nothing else has been detected within 20 km in the last 24 hours.
This page covers the record dated 8 November 2026. Browse recent observations in this area:
Reported by OpenAQ and the agency that runs each station 4 days ago.
It is the 3rd strongest of the 18 detections recorded within 20 km of this point since 9 March 2026. Another comparable one was recorded here earlier the same day. 10 more were recorded here in the fortnight before it.
What the source measured
OpenAQ and the agency that runs each station reported: PM2.5 24-hour mean 75.8 µg/m³ at Brent - John Keble Primary School, United Kingdom: Unhealthy, AQI 165 on the US EPA scale. 23 of 24 hours measured, ending 2026-11-08 21:00 UTC. Measured by a government monitoring agency via London Air Quality Network and OpenAQ; licence UK OGL "Open Government License".
The air quality index read 165 (Unhealthy) at the Brent - John Keble Primary School station.
Urban PEI: 117,694 within a heuristic 5 km radius; not unique people.
At this point we have recorded a air quality index between 164 and 166, over 14 readings since 8 November 2026. Today's reading sits 50% of the way up that range.
Nearby, since 9 March 2026
- November 8, 2026 · score 46 · 2.2 km
- April 17, 2026 · 5.1 km
- September 16, 2026 · score 50 · 6.4 km
How we know
One source: OpenAQ and the agency that runs each station. Not yet confirmed by a second, independent source.
Our own score for this event is 50 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v5. Rows carrying other versions were judged by different rules and are not directly comparable.
Series begins 8 March 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.
Event data
| Type | Air Quality |
| Severity | Medium |
| Calamity Score (ours) | 50 / 100 |
| Legacy data-support index | 0.69/1 |
| Coordinates | 51.5378, -0.2478 |
| Nearest city | Harlesden (0 km) |
| Urban exposure index (PEI) | 117.7K within 5 km |
| Impact tier | significant |
| Timestamp | 2026-11-08T21:00:00.000Z |
| Source | https://explore.openaq.org/locations/225719 |
| Licence | UK OGL "Open Government License" · London Air Quality Network, via OpenAQ |
Physical priority index · v5. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: openaq. Occurrence: 2026-11-08T21:00:00.000Z.
First archived: 2026-11-08T10:53:42.419Z. Material modification: 2026-11-08T23:12:18.531Z.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score breakdown
Technical details
| Aqi | 165 |
| AqiCategory | Unhealthy |
| AqiCategoryVersion | US-EPA-PM25-2024-05-06 |
| AqiProvenance | Calamity: US EPA PM2.5 24-hour breakpoints applied to the station's 24-hour mean; not an official AQI |
| Pm25 | 75.8 |
| MeasurementUnit | ug/m3 |
| AveragingPeriod | 24 hours |
| PeriodFrom | 2026-11-07T21:00:00.000Z |
| PeriodTo | 2026-11-08T21:00:00.000Z |
| HoursMeasured | 23 |
| LatestHourly | 90 |
| StationName | Brent - John Keble Primary School |
| StationId | 225719 |
| SensorId | 6955371 |
| Locality | Brent |
| Country | United Kingdom |
| CountryCode | GB |
| Provider | London Air Quality Network |
| Licence | UK OGL "Open Government License" |
| LicenceUrls | ["https://www.nationalarchives.gov.uk/doc/open-government-licence/version/2/"] |
Safety information
What to do when the air is unhealthy
Three things first, then what each level of the index means. From the US EPA’s AirNow.
For this reportAir Quality · Harlesden
Less effort outdoors
Shorten or move indoors hard activity; the worse the index, the more people it concerns.
AirNowKeep indoor air clean
Windows closed when the air outside is worse, an air purifier if you have one.
AirNowA real mask outside
A well-fitting N95/FFP2 filters fine particles; cloth and surgical masks do little.
AirNow
Before, during, after. Here it is “after”.
Before · When bad air is forecast
Follow the index
Your local air quality index and forecast.
Medicines at hand
If you have asthma or a heart or lung condition, keep your medicines with you.
AirNow (US EPA)
During · While the air is bad
Children, older people, the sick
They are the first to reduce effort outdoors.
Watch for symptoms
Coughing, breathlessness, chest pain: stop and get help if needed.
AirNow (US EPA)
After · When it improves
Air the house
When the outside air is better than inside.
AirNow (US EPA)
Questions people ask
What do the index levels mean?
0-50 good; 51-100 moderate; 101-150 unhealthy for sensitive groups; 151-200 unhealthy, for everyone; 201-300 very unhealthy; over 300 hazardous. Source: AirNow (US EPA).
Who are the sensitive groups?
People with heart or lung disease, older adults, children and teenagers, pregnant women and people who work or exercise outdoors. Source: AirNow (US EPA).
Review the area, threshold and delivery channel in your account.