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)
27
Good
Castro Valley, California
Last updated: ... (Local time)
Good
Fine
Moderate
Poor
Very poor
Hazardous
4.74 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
19.47 μg/m³
0
55
155
255
425
605+
17.33 ppb
0
55
71
86
201
201+
0.65 ppb
0
36
76
186
605
1005+
1.83 ppb
0
54
101
361
1250
2050+
0.24 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Castro Valley, California
Castro Valley, California
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AQI 27
Good
4.92μg/m³
PM2.5
21.52μg/m³
PM10
15.45ppb
O3
0.77ppb
SO2
5.60ppb
NO2
0.12ppm
CO
AQI 27
Good
4.92μg/m³
PM2.5
21.52μg/m³
PM10
15.45ppb
O3
0.77ppb
SO2
5.60ppb
NO2
0.12ppm
CO
AQI 27
Good
4.95μg/m³
PM2.5
21.57μg/m³
PM10
15.35ppb
O3
0.76ppb
SO2
5.53ppb
NO2
0.12ppm
CO
AQI 27
Good
5.02μg/m³
PM2.5
21.45μg/m³
PM10
14.84ppb
O3
0.69ppb
SO2
5.10ppb
NO2
0.11ppm
CO
AQI 27
Good
5.14μg/m³
PM2.5
22.00μg/m³
PM10
14.48ppb
O3
0.69ppb
SO2
5.12ppb
NO2
0.11ppm
CO
AQI 27
Good
5.00μg/m³
PM2.5
21.30μg/m³
PM10
14.62ppb
O3
0.63ppb
SO2
4.79ppb
NO2
0.11ppm
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 11:00:00 on 2025-07-29.
In the last 24 hours, the best air quality in Castro Valley, California was observed at 06:00:00 on 2025-07-29.
As of now, the AQI in Castro Valley, California is 27, indicating Good 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 4.982 μg/m3.
The PM10 concentration in Castro Valley, California is 21.77 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Castro Valley, California is 0.116 ppm.
Currently, Castro Valley, California has a sulfur dioxide (SO2) concentration of 0.761 ppb.
The current ozone (O3) level in Castro Valley, California at the moment is 15.377 ppm.
Nitrogen dioxide (NO2) level in Castro Valley, California at the moment is 5.54 ppb.
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