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)
33
Good
Johnstown, Colorado
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
6.14 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
24.81 μg/m³
0
55
155
255
425
605+
17.01 ppb
0
55
71
86
201
201+
0.56 ppb
0
36
76
186
605
1005+
9.13 ppb
0
54
101
361
1250
2050+
0.19 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Johnstown, Colorado
Johnstown, Colorado
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AQI 25
Good
4.15μg/m³
PM2.5
16.14μg/m³
PM10
26.66ppb
O3
0.51ppb
SO2
6.66ppb
NO2
0.16ppm
CO
AQI 27
Good
4.50μg/m³
PM2.5
19.95μg/m³
PM10
29.35ppb
O3
0.52ppb
SO2
5.19ppb
NO2
0.14ppm
CO
AQI 27
Good
4.73μg/m³
PM2.5
21.03μg/m³
PM10
23.31ppb
O3
0.52ppb
SO2
4.34ppb
NO2
0.14ppm
CO
AQI 27
Good
5.25μg/m³
PM2.5
23.60μg/m³
PM10
26.97ppb
O3
0.51ppb
SO2
10.54ppb
NO2
0.19ppm
CO
AQI 27
Good
5.20μg/m³
PM2.5
23.04μg/m³
PM10
27.82ppb
O3
0.51ppb
SO2
10.65ppb
NO2
0.19ppm
CO
AQI 27
Good
4.84μg/m³
PM2.5
21.48μg/m³
PM10
24.17ppb
O3
0.52ppb
SO2
5.86ppb
NO2
0.15ppm
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 12:00:00 on 2026-09-07.
In the last 24 hrs, the best air quality in Johnstown, Colorado was observed at 12:00:00 on 2026-09-06.
The current air quality in Johnstown, Colorado is 33, categorized as Good based on real-time data.
The most common pollutant in Johnstown, Colorado is PM2.5.
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 6.14 μg/m3.
The current PM10 concentration at Johnstown, Colorado is 24.807 μg/m3.
The current carbon monoxide (CO) concentration at Johnstown, Colorado is 0.191 ppm.
The current sulfur dioxide (SO2) concentration at Johnstown, Colorado is 0.565 ppb.
The current ozone (O3) concentration at Johnstown, Colorado is 17.009 ppm.
The current nitrogen dioxide (NO2) concentration at Johnstown, Colorado is 9.131 ppb.
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