Stay updated with real-time air quality in Castro Valley, California featuring accurate data on AQI, PM2.5, PM10, O3, NO2, SO2, and CO levels. Use our interactive map and detailed forecasts to monitor pollution trends, manage health risks, and plan your daily activities with confidence.
Live AQI (Air Quality Index)
52
Moderate
Castro Valley, California
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
9.65 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
35.75 μg/m³
0
55
155
255
425
605+
32.93 ppb
0
55
71
86
201
201+
0.58 ppb
0
36
76
186
605
1005+
3.88 ppb
0
54
101
361
1250
2050+
0.24 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Castro Valley, California
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AQI 49
Good
9.16μg/m³
PM2.5
31.36μg/m³
PM10
33.28ppb
O3
0.62ppb
SO2
3.40ppb
NO2
0.24ppm
CO
AQI 49
Good
9.16μg/m³
PM2.5
31.36μg/m³
PM10
33.28ppb
O3
0.62ppb
SO2
3.40ppb
NO2
0.24ppm
CO
AQI 49
Good
9.47μg/m³
PM2.5
34.11μg/m³
PM10
32.98ppb
O3
0.60ppb
SO2
3.53ppb
NO2
0.24ppm
CO
AQI 54
Moderate
11.20μg/m³
PM2.5
48.07μg/m³
PM10
31.60ppb
O3
0.50ppb
SO2
4.20ppb
NO2
0.23ppm
CO
AQI 54
Moderate
11.03μg/m³
PM2.5
46.20μg/m³
PM10
31.27ppb
O3
0.48ppb
SO2
4.10ppb
NO2
0.24ppm
CO
AQI 56
Moderate
12.19μg/m³
PM2.5
55.50μg/m³
PM10
30.86ppb
O3
0.48ppb
SO2
3.88ppb
NO2
0.22ppm
CO
Air quality and pollutant data for California, USA are sourced from ground-based monitors and satellites, adhering to US EPA standards. Machine learning and advanced algorithms enhance the data by incorporating local variables like traffic and population density, ensuring high accuracy and dependability.
Source: Ambee Data Sources
The air quality information for Castro Valley, California is updated every hour for accuracy.
In the past 24 hours, the air quality in Castro Valley, California was at its worst at 03:00:00 on 2026-03-09.
In the last 24 hours, the best air quality in Castro Valley, California was observed at 04:00:00 on 2026-03-09.
As of now, the AQI in Castro Valley, California is 52, indicating Moderate conditions.
Castro Valley, California air has the highest levels of PM2.5.
Poor air quality in Castro Valley, California means it's advisable to stay indoors and wear a mask for your protection.
PM2.5 levels in Castro Valley, California are currently 9.655 μg/m3.
The PM10 concentration in Castro Valley, California is 35.752 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Castro Valley, California is 0.24 ppm.
Currently, Castro Valley, California has a sulfur dioxide (SO2) concentration of 0.582 ppb.
The current ozone (O3) level in Castro Valley, California at the moment is 32.928 ppm.
Nitrogen dioxide (NO2) level in Castro Valley, California at the moment is 3.878 ppb.
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