Worst air pollution Kiryū, today and tomorrow
Today (21 September): Air quality in Kiryū is fair. AQI and NO2 are fair; PM2.5, PM10, O3, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 4:00 PM (NO2: 21.2/100).
Tomorrow (22 September 2026): Air quality in Kiryū is moderate. AQI worsens to moderate; NO2 increases to moderate; O3 increases to fair; all other pollutants stay as today. Pollution peaks around 6:00 PM (NO2: 42.5/100). 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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Kiryū's air quality reflects the flat Gunma Prefecture Watarase River valley position, with vehicle traffic on surrounding roads and the traditional textile — Kiryu being Japan's historic silk weaving capital — and manufacturing corridor contributing distinctive textile dust and dye chemical emissions alongside primary vehicle sources. The flat Kanto Plain edge allows reasonable dispersal, while summer photochemical ozone from the Kanto corridor is the primary warm-season concern and the textile industry's distinctive silk and dye emissions represent Kiryu's most locally unique air quality characteristic throughout the year.
Today - 21 September | Pollution peaks at 16:00
AQI:
Fair
21.2/100
PM2.5 (fine particles):
Good
4.0/100
PM10 (coarse particles):
Good
3.6/100
NO2 (nitrogen dioxide):
Fair
21.2/100
O3 (ozone):
Good
14.2/100
SO2 (sulfur dioxide):
Good
1.5/100
CO (carbon monoxide):
Good
0.6/100
HCHO (formaldehyde):
Good
7.1/100
PM1 (ultrafine particles):
Good
1.9/100
Levels show the poorest local air quality during the day
Tomorrow - 22 September | Pollution peaks at 18:00
AQI:
Moderate
42.5/100
PM2.5 (fine particles):
Good
19.5/100
PM10 (coarse particles):
Good
14.7/100
NO2 (nitrogen dioxide):
Moderate
42.5/100
O3 (ozone):
Fair
27.8/100
SO2 (sulfur dioxide):
Good
7.7/100
CO (carbon monoxide):
Good
1.0/100
HCHO (formaldehyde):
Good
9.6/100
PM1 (ultrafine particles):
Good
12.0/100
Frequently Asked Questions
Is air quality bad in Kiryū right now?
On 21 September 2026, overall air quality in Kiryū is fair. AQI is the main air quality indicator at 21.2/100. Pollution peaks around 4:00 PM (NO2: 21.2/100).
Will air quality be worse tomorrow in Kiryū?
On 22 September 2026, air quality conditions in Kiryū will be worse than today, with AQI forecast at moderate at 42.5/100. Pollution peaks around 6:00 PM (NO2: 42.5/100).
When is air pollution at its worst in Kiryū?
Air quality in Kiryū tends to be worse when traffic emissions, steel, cement, and chemical production, together with textile and manufacturing operations build up and dry, windy weather picks up. These wind events can carry dust in from the surrounding arid landscape. Heat and sunlight combine with emissions to form ozone at ground level.
Are air quality levels in Kiryū 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: 22 September 2026 at 02:59 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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