Worst air pollution Nagano, today and tomorrow
Today (16 July): Air quality in Nagano is fair. NO2 and HCHO are fair; AQI and O3 are medium; PM2.5, PM10, SO2, CO, and PM1 are good. Pollution peaks around 1:00 PM (O3: 43.7/100).
Tomorrow (17 July 2026): Air quality in Nagano is fair. NO2 decreases to good; all other pollutants stay as today. Pollution peaks around 12:00 PM (O3: 54.8/100). 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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Nagano's air quality benefits from its elevated Nagano Basin position at 371 metres surrounded by the Japanese Alps, with vehicle traffic on surrounding roads and the precision manufacturing, Winter Olympics legacy, and tourism corridor contributing local sources. The surrounding Northern Alps create dramatic topographic variation and winter inversions in the enclosed mountain basin create seasonal challenges, while summer conditions are generally excellent with clean Alpine westerly airflows providing outstanding conditions throughout the warmer months.
Today - 16 July | Pollution peaks at 13:00
AQI:
Medium
43.7/100
PM2.5 (fine particles):
Good
12.8/100
PM10 (coarse particles):
Good
3.9/100
NO2 (nitrogen dioxide):
Fair
21.6/100
O3 (ozone):
Medium
43.7/100
SO2 (sulfur dioxide):
Good
4.9/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Fair
20.6/100
PM1 (ultrafine particles):
Good
15.5/100
Levels show the poorest local air quality during the day
Tomorrow - 17 July | Pollution peaks at 12:00
AQI:
Medium
54.8/100
PM2.5 (fine particles):
Good
9.6/100
PM10 (coarse particles):
Good
2.8/100
NO2 (nitrogen dioxide):
Good
19.5/100
O3 (ozone):
Medium
54.8/100
SO2 (sulfur dioxide):
Good
7.5/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Fair
20.2/100
PM1 (ultrafine particles):
Good
11.8/100
Frequently Asked Questions
Is air quality bad in Nagano right now?
On 16 July 2026, overall air quality in Nagano is fair. NO2 is the main pollutant at 21.6/100. Pollution peaks around 1:00 PM (O3: 43.7/100).
Will air quality be worse tomorrow in Nagano?
On 17 July 2026, air quality conditions in Nagano will be similar to today, with HCHO forecast at fair at 20.2/100. Pollution peaks around 12:00 PM (O3: 54.8/100).
When is air pollution at its worst in Nagano?
Pollution in Nagano typically rises when road traffic, manufacturing and food processing, as well as seasonal tourism traffic combine, especially once temperature inversions set in over the valley. The bowl-like terrain here limits how quickly pollutants can escape. This is most pronounced in winter, when inversions are more frequent.
Are air quality levels in Nagano 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