Stay updated with real-time air quality in Johnstown, 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)
44
Good
Johnstown, Colorado
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
3.46 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
22.58 μg/m³
0
55
155
255
425
605+
48.11 ppb
0
55
71
86
201
201+
0.71 ppb
0
36
76
186
605
1005+
1.22 ppb
0
54
101
361
1250
2050+
0.13 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Johnstown, Colorado
Johnstown, Colorado
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AQI 45
Good
3.26μg/m³
PM2.5
26.40μg/m³
PM10
48.85ppb
O3
0.70ppb
SO2
1.52ppb
NO2
0.14ppm
CO
AQI 44
Good
3.23μg/m³
PM2.5
25.96μg/m³
PM10
47.27ppb
O3
0.73ppb
SO2
0.85ppb
NO2
0.12ppm
CO
AQI 45
Good
2.94μg/m³
PM2.5
22.17μg/m³
PM10
48.59ppb
O3
0.74ppb
SO2
0.31ppb
NO2
0.11ppm
CO
AQI 46
Good
2.41μg/m³
PM2.5
16.54μg/m³
PM10
49.77ppb
O3
0.70ppb
SO2
1.29ppb
NO2
0.11ppm
CO
AQI 46
Good
2.13μg/m³
PM2.5
9.67μg/m³
PM10
49.65ppb
O3
0.71ppb
SO2
1.28ppb
NO2
0.11ppm
CO
AQI 45
Good
2.80μg/m³
PM2.5
20.57μg/m³
PM10
48.83ppb
O3
0.73ppb
SO2
0.55ppb
NO2
0.11ppm
CO
Air quality data and pollutant measurements for Colorado, USA adhere to strict US EPA standards. The data is collected from multiple reliable sources, including satellites and ground-based monitoring stations. This data is further analyzed and enhanced using machine learning and advanced algorithms that factor in elements such as traffic and population density, ensuring accurate and reliable results.
Source: Ambee Data Sources
The air quality for Johnstown, Colorado is updated every hour.
The worst air quality in Johnstown, Colorado in the last 24 hours was observed at 10:00:00 on 2026-06-12.
In the last 24 hrs, the best air quality in Johnstown, Colorado was observed at 09:00:00 on 2026-06-13.
The current air quality in Johnstown, Colorado is 44, categorized as Good based on real-time data.
The most common pollutant in Johnstown, Colorado is O3.
If the air quality in Johnstown, Colorado is poor, consider staying indoors and wearing a mask to protect yourself.
The current PM2.5 concentration at Johnstown, Colorado is 3.459 μg/m3.
The current PM10 concentration at Johnstown, Colorado is 22.58 μg/m3.
The current carbon monoxide (CO) concentration at Johnstown, Colorado is 0.128 ppm.
The current sulfur dioxide (SO2) concentration at Johnstown, Colorado is 0.709 ppb.
The current ozone (O3) concentration at Johnstown, Colorado is 48.107 ppm.
The current nitrogen dioxide (NO2) concentration at Johnstown, Colorado is 1.219 ppb.
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