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)
33
Good
Castro Valley, California
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
5.95 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
23.75 μg/m³
0
55
155
255
425
605+
30.89 ppb
0
55
71
86
201
201+
0.45 ppb
0
36
76
186
605
1005+
6.62 ppb
0
54
101
361
1250
2050+
0.32 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Moderate
Castro Valley, California
Castro Valley, California
Scroll To Air Quality MapLoading...
AQI 33
Good
6.05μg/m³
PM2.5
23.57μg/m³
PM10
31.70ppb
O3
0.47ppb
SO2
6.48ppb
NO2
0.32ppm
CO
AQI 33
Good
6.05μg/m³
PM2.5
23.57μg/m³
PM10
31.70ppb
O3
0.47ppb
SO2
6.48ppb
NO2
0.32ppm
CO
AQI 33
Good
6.04μg/m³
PM2.5
23.92μg/m³
PM10
31.15ppb
O3
0.46ppb
SO2
6.48ppb
NO2
0.32ppm
CO
AQI 33
Good
5.78μg/m³
PM2.5
24.32μg/m³
PM10
28.42ppb
O3
0.44ppb
SO2
6.32ppb
NO2
0.31ppm
CO
AQI 33
Good
6.21μg/m³
PM2.5
26.02μg/m³
PM10
28.62ppb
O3
0.44ppb
SO2
6.11ppb
NO2
0.30ppm
CO
AQI 27
Good
5.27μg/m³
PM2.5
22.62μg/m³
PM10
27.02ppb
O3
0.44ppb
SO2
5.87ppb
NO2
0.30ppm
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 12:00:00 on 2026-02-08.
In the last 24 hours, the best air quality in Castro Valley, California was observed at 11:00:00 on 2026-02-08.
As of now, the AQI in Castro Valley, California is 33, 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 5.949 μg/m3.
The PM10 concentration in Castro Valley, California is 23.749 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Castro Valley, California is 0.319 ppm.
Currently, Castro Valley, California has a sulfur dioxide (SO2) concentration of 0.45 ppb.
The current ozone (O3) level in Castro Valley, California at the moment is 30.892 ppm.
Nitrogen dioxide (NO2) level in Castro Valley, California at the moment is 6.618 ppb.
All Rights Reserved © Ambee Inc. 2025