Worst air pollution Miyoshi, Hiroshima, today and tomorrow
Today (21 September): Air quality in Miyoshi, Hiroshima is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 11:00 PM (O3: 29.8/100).
Tomorrow (22 September 2026): Air quality in Miyoshi, Hiroshima is fair. All pollutants stay as today. Pollution peaks around 1:00 AM (O3: 30.5/100). 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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Miyoshi in Hiroshima reflects the Hiroshima Prefecture Tomoe River valley's partial enclosure in the Chugoku highland, with vehicle traffic on surrounding roads and the agriculture, services, and manufacturing corridor contributing local sources. The surrounding Chugoku Mountains create significant topographic variation, while winter valley inversions create seasonal challenges and Miyoshi generally maintains moderate to good conditions for a major Japanese Chugoku inland highland city throughout most of the year.
Today - 21 September | Pollution peaks at 23:00
AQI:
Fair
29.8/100
PM2.5 (fine particles):
Good
16.1/100
PM10 (coarse particles):
Good
15.4/100
NO2 (nitrogen dioxide):
Good
4.0/100
O3 (ozone):
Fair
29.8/100
SO2 (sulfur dioxide):
Good
0.7/100
CO (carbon monoxide):
Good
0.6/100
HCHO (formaldehyde):
Good
2.8/100
PM1 (ultrafine particles):
Good
5.1/100
Levels show the poorest local air quality during the day
Tomorrow - 22 September | Pollution peaks at 01:00
AQI:
Fair
30.5/100
PM2.5 (fine particles):
Good
15.7/100
PM10 (coarse particles):
Good
14.8/100
NO2 (nitrogen dioxide):
Good
5.4/100
O3 (ozone):
Fair
30.5/100
SO2 (sulfur dioxide):
Good
0.7/100
CO (carbon monoxide):
Good
0.6/100
HCHO (formaldehyde):
Good
3.2/100
PM1 (ultrafine particles):
Good
4.4/100
Frequently Asked Questions
Is air quality bad in Miyoshi, Hiroshima right now?
On 21 September 2026, overall air quality in Miyoshi, Hiroshima is fair. AQI is the main air quality indicator at 29.8/100. Pollution peaks around 11:00 PM (O3: 29.8/100).
Will air quality be worse tomorrow in Miyoshi, Hiroshima?
On 22 September 2026, air quality conditions in Miyoshi, Hiroshima will be similar to today, with AQI forecast at fair at 30.5/100. Pollution peaks around 1:00 AM (O3: 30.5/100).
When is air pollution at its worst in Miyoshi, Hiroshima?
Pollution in Miyoshi typically rises when traffic on the surrounding roads, light manufacturing, along with farming and agricultural processing combine, especially once temperature inversions set in over the valley. Topographic enclosure in the valley lets pollution accumulate rather than clear out. This tends to happen most in winter, when inversions are most common.
Are air quality levels in Miyoshi, Hiroshima 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.
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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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