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Iiyama (Nagano) (JP)

Air Quality Trend (last 7 days)

Good (0-50)
Moderate (51-100)
Unhealthy for Sensitive Groups (101-150)
Unhealthy (151-200)
Very Unhealthy (201-300)
Hazardous (300+)

Weather - 48h MET Norway

Heavy rain
14°C
Heavy rain
Humidity
84.4%
Wind
7 m/s
Pressure
1003.8 hPa
Direction
189°
Sunrise
04:00
Sunset
16:00
24h Forecast:
Temp.
12° / 18°
Precip.
24.9mm
Max wind
7.7 m/s

Hourly Forecast

09.04
Now
Weather
14°
1.3
7
09.04
21:00
Weather
14°
0.5
7
09.04
22:00
Weather
15°
1.2
7
09.04
23:00
Weather
15°
2
8
10.04
00:00
Weather
15°
1.4
7
10.04
01:00
Weather
16°
1.7
7
10.04
02:00
Weather
18°
1.2
7
10.04
03:00
Weather
16°
1.2
8
10.04
04:00
Weather
18°
2.6
7
10.04
05:00
Weather
17°
4
10.04
06:00
Weather
17°
4.4
5
10.04
07:00
Weather
17°
2.9
10.04
08:00
Weather
16°
0.2
10.04
09:00
Weather
17°
10.04
10:00
Weather
16°
10.04
11:00
Weather
16°
10.04
12:00
Weather
15°
10.04
13:00
Weather
14°
10.04
14:00
Weather
14°
10.04
15:00
Weather
14°
10.04
16:00
Weather
13°
10.04
17:00
Weather
13°
10.04
18:00
Weather
12°
10.04
19:00
Weather
12°
0.3

Temperature

18°C
12°C
20:00
14°C
21:00
14°C
22:00
15°C
23:00
15°C
00:00
15°C
01:00
16°C
02:00
18°C
03:00
16°C
04:00
18°C
05:00
17°C
06:00
17°C
07:00
17°C
08:00
16°C
09:00
17°C
10:00
16°C
11:00
16°C
12:00
15°C
13:00
14°C
14:00
14°C
15:00
14°C
16:00
13°C
17:00
13°C
18:00
12°C
19:00
12°C
20:00 07:00 19:00

Precipitation

4.4mm
0mm
20:00
1.3mm
21:00
0.5mm
22:00
1.2mm
23:00
2mm
00:00
1.4mm
01:00
1.7mm
02:00
1.2mm
03:00
1.2mm
04:00
2.6mm
05:00
4mm
06:00
4.4mm
07:00
2.9mm
08:00
0.2mm
19:00
0.3mm
20:00 07:00 19:00

Wind

7.7m/s
0m/s
20:00
6.5 m/s
21:00
6.6 m/s
22:00
7.1 m/s
23:00
7.5 m/s
00:00
7.4 m/s
01:00
7.4 m/s
02:00
7.4 m/s
03:00
7.7 m/s
04:00
7.2 m/s
05:00
4.9 m/s
06:00
5.1 m/s
07:00
4 m/s
08:00
2.9 m/s
09:00
3.2 m/s
10:00
2.5 m/s
11:00
2.6 m/s
12:00
1.6 m/s
13:00
1.9 m/s
14:00
2.1 m/s
15:00
2 m/s
16:00
2 m/s
17:00
2 m/s
18:00
2 m/s
19:00
1.7 m/s
20:00 07:00 19:00

Radiation

No sensor within 100 km.

We display the worst measurements from all stations in the area. This approach provides a more cautious assessment of air quality, accounting for local pollution sources.

AQI
6.3 km
8
2.7%

Measurement time: 2026-04-09 22:14

Calculated from PM2.5/PM10

O3
6.3 km
104.15 µg/m3
65.1%

Measurement time: 2026-04-09 22:14

source: OpenWeatherMap

PM2.5
6.3 km
1.97 µg/m3
2.3%

Measurement time: 2026-04-09 22:14

source: OpenWeatherMap

PM10
6.3 km
2.17 µg/m3
1.6%

Measurement time: 2026-04-09 22:14

source: OpenWeatherMap

CO
6.3 km
0.16197 mg/m3
1.2%

Measurement time: 2026-04-09 22:14

source: OpenWeatherMap

NO2
6.3 km
0.96 µg/m3
0.5%

Measurement time: 2026-04-09 22:14

source: OpenWeatherMap

SO2
6.3 km
0.37 µg/m3
0.1%

Measurement time: 2026-04-09 22:14

source: OpenWeatherMap

Info


Country: Japan
Region: Nagano
Latitude: 36.85
Longitude: 138.36667


Solar Energy

Low
242.9 W/m²
Solar Radiation
Solar Calculator
Calculate energy production for Iiyama

About Air Quality in Iiyama

Air quality in Iiyama is monitored in real-time by sensors and measurement stations. On this page you'll find current data on major air pollutants including particulate matter PM2.5 and PM10, nitrogen dioxide (NO2), ozone (O3), and radiation levels.

Common Pollutants in Iiyama

  • PM2.5 - fine particulate matter up to 2.5 micrometers, particularly harmful to health
  • PM10 - particulate matter up to 10 micrometers from traffic and industry
  • NO2 - nitrogen dioxide mainly emitted by vehicles
  • O3 - tropospheric ozone formed in photochemical reactions

When is Air Quality Best in Iiyama?

Generally, the best air quality occurs:

  • Early morning (5:00-7:00 AM) before rush hour traffic
  • After rainfall which cleanses the atmosphere
  • During strong winds that disperse pollutants
  • In summer months when heating systems are less used

Tips for Runners in Iiyama

If you're planning outdoor activities in Iiyama, always check the current AQI value. When AQI exceeds 100, consider moving your workout indoors or shortening the distance. People with respiratory issues, children, and seniors should be especially cautious during elevated pollution levels. Choose routes away from busy streets and industrial areas.