Worst air pollution Hōyachō, today and tomorrow
Today (10 August): Air quality in Hōyachō is medium. AQI and O3 are medium; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 1:00 PM (O3: 43.9/100).
Tomorrow (11 August 2026): Air quality in Hōyachō is fair. AQI worsens to fair; O3 increases to fair; all other pollutants stay as today. Pollution peaks around 3:00 PM (O3: 38.4/100). 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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Hōyachō in Tokyo reflects the western Tokyo metropolitan suburban corridor in Higashiyamato city, with vehicle traffic on surrounding roads and the manufacturing and residential character contributing local sources. The flat Kanto Plain allows reasonable dispersal, while the broader Tokyo metropolitan regional emissions elevate background and summer photochemical ozone is the primary warm-season concern and the area generally maintains moderate Tokyo western suburban readings throughout most of the year.
Today - 10 August | Pollution peaks at 13:00
AQI:
Medium
43.9/100
PM2.5 (fine particles):
Good
12.2/100
PM10 (coarse particles):
Good
3.9/100
NO2 (nitrogen dioxide):
Good
15.1/100
O3 (ozone):
Medium
43.9/100
SO2 (sulfur dioxide):
Good
10.4/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
8.8/100
PM1 (ultrafine particles):
Good
13.3/100
Levels show the poorest local air quality during the day
Tomorrow - 11 August | Pollution peaks at 15:00
AQI:
Fair
38.4/100
PM2.5 (fine particles):
Good
9.8/100
PM10 (coarse particles):
Good
2.7/100
NO2 (nitrogen dioxide):
Good
11.4/100
O3 (ozone):
Fair
38.4/100
SO2 (sulfur dioxide):
Good
7.9/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
7.8/100
PM1 (ultrafine particles):
Good
13.9/100
Frequently Asked Questions
Is air quality bad in Hōyachō right now?
On 10 August 2026, overall air quality in Hōyachō is medium. AQI is the main air quality indicator at 43.9/100. Pollution peaks around 1:00 PM (O3: 43.9/100).
Will air quality be worse tomorrow in Hōyachō?
On 11 August 2026, air quality conditions in Hōyachō will be worse than today, with AQI forecast at fair at 38.4/100. Pollution peaks around 3:00 PM (O3: 38.4/100).
When is air pollution at its worst in Hōyachō?
Hōyachō usually sees its poorest air quality when vehicle traffic, heavy industrial and chemical processing, together with textile and manufacturing operations coincide with periods when warm, sunny weather takes hold. Heat and sunlight combine with emissions to form ozone at ground level. This is far less of an issue outside the warmer months.
Are air quality levels in Hōyachō 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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