Stay updated with real-time air quality in Castle Rock, Colorado 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)
39
Good
Castle Rock, Colorado
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
0.83 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
3.14 μg/m³
0
55
155
255
425
605+
42.02 ppb
0
55
71
86
201
201+
0.60 ppb
0
36
76
186
605
1005+
16.42 ppb
0
54
101
361
1250
2050+
0.32 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Castle Rock, Colorado
Castle Rock, Colorado
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AQI 31
Good
0.93μg/m³
PM2.5
4.05μg/m³
PM10
32.90ppb
O3
0.48ppb
SO2
23.21ppb
NO2
0.29ppm
CO
AQI 33
Good
0.94μg/m³
PM2.5
2.64μg/m³
PM10
36.03ppb
O3
0.45ppb
SO2
21.54ppb
NO2
0.23ppm
CO
AQI 33
Good
0.92μg/m³
PM2.5
2.64μg/m³
PM10
36.08ppb
O3
0.45ppb
SO2
19.93ppb
NO2
0.24ppm
CO
AQI 31
Good
0.95μg/m³
PM2.5
4.25μg/m³
PM10
32.96ppb
O3
0.48ppb
SO2
23.34ppb
NO2
0.29ppm
CO
AQI 31
Good
0.75μg/m³
PM2.5
2.53μg/m³
PM10
33.23ppb
O3
0.47ppb
SO2
23.09ppb
NO2
0.28ppm
CO
AQI 31
Good
0.93μg/m³
PM2.5
4.12μg/m³
PM10
33.04ppb
O3
0.48ppb
SO2
23.36ppb
NO2
0.29ppm
CO
Air quality measurements for Colorado, USA meet strict US EPA standards. These measurements are collected from reliable sources, including satellites and ground-based monitoring systems. Advanced algorithms and machine learning techniques are applied to the data, factoring in variables such as traffic and population density, to ensure precision and reliability.
Source: Ambee Data Sources
Air quality data for Castle Rock, Colorado is updated on an hourly basis.
The worst air quality in Castle Rock, Colorado was recorded at 11:00:00 on 2025-12-10.
The best air quality in Castle Rock, Colorado was recorded at 04:00:00 on 2025-12-10.
The real-time air quality index in Castle Rock, Colorado is 39, currently categorized as Good.
The most common pollutant in Castle Rock, Colorado is O3.
If the air quality in Castle Rock, Colorado is poor, limit outdoor activities and use a mask to safeguard your health.
The measured PM2.5 levels in Castle Rock, Colorado at present are 0.833 μg/m3.
The current PM10 levels in Castle Rock, Colorado are 3.136 μg/m3.
The current carbon monoxide (CO) level in Castle Rock, Colorado is 0.319 ppm.
The current sulfur dioxide (SO2) levels in Castle Rock, Colorado are 0.605 ppb.
The current ozone (O3) levels at Castle Rock, Colorado is 42.016 ppm.
The current nitrogen dioxide (NO2) levels at Castle Rock, Colorado is 16.418 ppb.
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