Worst air pollution Chikuma, today and tomorrow
Today (16 July): Air quality in Chikuma is fair. NO2 and PM1 are fair; AQI and O3 are medium; PM2.5, PM10, SO2, CO, and HCHO are good. Pollution peaks around 12:00 PM (O3: 45.3/100).
Tomorrow (17 July 2026): Air quality in Chikuma is medium. NO2 decreases to good; PM1 decreases to good; all other pollutants stay as today. Pollution peaks around 1:00 PM (O3: 53.2/100). 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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Chikuma's air quality reflects the Nagano Prefecture Chikuma River valley position at 371 metres between the Honshu Alps and the Nagano Basin, with vehicle traffic on surrounding roads and the rice farming, apple, and manufacturing corridor contributing local sources. The surrounding Japanese Alps create topographic variation, while winter valley inversions create seasonal challenges and Chikuma generally maintains moderate to good conditions for a major Japanese Nagano Basin valley city throughout most of the year.
Today - 16 July | Pollution peaks at 12:00
AQI:
Medium
45.3/100
PM2.5 (fine particles):
Good
18.0/100
PM10 (coarse particles):
Good
5.1/100
NO2 (nitrogen dioxide):
Fair
21.0/100
O3 (ozone):
Medium
45.3/100
SO2 (sulfur dioxide):
Good
5.4/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
13.9/100
PM1 (ultrafine particles):
Fair
22.4/100
Levels show the poorest local air quality during the day
Tomorrow - 17 July | Pollution peaks at 13:00
AQI:
Medium
53.2/100
PM2.5 (fine particles):
Good
9.3/100
PM10 (coarse particles):
Good
2.5/100
NO2 (nitrogen dioxide):
Good
12.7/100
O3 (ozone):
Medium
53.2/100
SO2 (sulfur dioxide):
Good
3.9/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
14.2/100
PM1 (ultrafine particles):
Good
12.8/100
Frequently Asked Questions
Is air quality bad in Chikuma right now?
On 16 July 2026, overall air quality in Chikuma is fair. PM1 is the main pollutant at 22.4/100. Pollution peaks around 12:00 PM (O3: 45.3/100).
Will air quality be worse tomorrow in Chikuma?
On 17 July 2026, air quality conditions in Chikuma will be better than today, with AQI forecast at medium at 53.2/100. Pollution peaks around 1:00 PM (O3: 53.2/100).
When is air pollution at its worst in Chikuma?
Pollution in Chikuma typically rises when vehicle traffic, manufacturing and food processing, along with farming and agricultural processing combine, especially once calm, stagnant conditions settle in the surrounding 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 Chikuma 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.
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Data provided by Airmine — Last update: 16 July 2026 at 10:33 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.
For long term forecasts and maps, see the Airmine app