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Castro Valley (California) (US)

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

Fair
15°C
Fair
Humidity
84.9%
Wind
3 m/s
Pressure
1013.3 hPa
Direction
287°
Sunrise
04:00
Sunset
16:00
24h Forecast:
Temp.
13° / 17°
Precip.
30.7mm
Max wind
6.4 m/s

Hourly Forecast

10.04
Now
Weather
15°
10.04
05:00
Weather
14°
10.04
06:00
Weather
14°
10.04
07:00
Weather
15°
10.04
08:00
Weather
14°
10.04
09:00
Weather
14°
10.04
10:00
Weather
14°
0.1
10.04
11:00
Weather
14°
1.4
10.04
12:00
Weather
13°
2.6
10.04
13:00
Weather
13°
4.6
5
10.04
14:00
Weather
13°
1
10.04
15:00
Weather
13°
1
10.04
16:00
Weather
14°
0.5
10.04
17:00
Weather
14°
0.7
10.04
18:00
Weather
16°
0.4
10.04
19:00
Weather
17°
0.4
10.04
20:00
Weather
17°
2.1
10.04
21:00
Weather
17°
2.1
6
10.04
22:00
Weather
17°
0.4
10.04
23:00
Weather
17°
3.6
6
11.04
00:00
Weather
16°
1.6
5
11.04
01:00
Weather
15°
1.8
5
11.04
02:00
Weather
14°
4.5
5
11.04
03:00
Weather
13°
1.9

Temperature

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

Precipitation

4.6mm
0mm
10:00
0.1mm
11:00
1.4mm
12:00
2.6mm
13:00
4.6mm
14:00
1mm
15:00
1mm
16:00
0.5mm
17:00
0.7mm
18:00
0.4mm
19:00
0.4mm
20:00
2.1mm
21:00
2.1mm
22:00
0.4mm
23:00
3.6mm
00:00
1.6mm
01:00
1.8mm
02:00
4.5mm
03:00
1.9mm
04:00 15:00 03:00

Wind

6.4m/s
0m/s
04:00
3 m/s
05:00
2.5 m/s
06:00
1.4 m/s
07:00
0.7 m/s
08:00
1.3 m/s
09:00
1.7 m/s
10:00
2.7 m/s
11:00
3.7 m/s
12:00
4.4 m/s
13:00
5.1 m/s
14:00
3.3 m/s
15:00
2.7 m/s
16:00
3.7 m/s
17:00
4.1 m/s
18:00
3.9 m/s
19:00
4.4 m/s
20:00
4.3 m/s
21:00
6 m/s
22:00
4.9 m/s
23:00
6.4 m/s
00:00
5.2 m/s
01:00
5.3 m/s
02:00
5.3 m/s
03:00
4.4 m/s
04:00 15:00 03:00

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
74.6 km
59
19.7%

Measurement time: 2026-04-10 04:00

Calculated from PM2.5/PM10

O3
34.2 km
72.71 µg/m3
45.4%

Measurement time: 2026-04-10 04:00

source: OpenWeatherMap

PM2.5
74.6 km
16 µg/m3
19%

Measurement time: 2026-04-10 04:00

source: Aqicn

PM10
74.6 km
18 µg/m3
12.9%

Measurement time: 2026-04-10 04:00

source: Aqicn

NO2
77 km
3.95 µg/m3
2%

Measurement time: 2026-04-10 06:11

source: OpenWeatherMap

CO
77 km
0.12265 mg/m3
0.9%

Measurement time: 2026-04-10 06:11

source: OpenWeatherMap

SO2
77 km
0.88 µg/m3
0.3%

Measurement time: 2026-04-10 06:11

source: OpenWeatherMap

Info


Region: California
Latitude: 37.6941
Longitude: -122.08635


Solar Energy

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0 W/m²
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About Air Quality in Castro Valley

Air quality in Castro Valley 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 Castro Valley

  • 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 Castro Valley?

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 Castro Valley

If you're planning outdoor activities in Castro Valley, 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.