Stay updated with real-time air quality in Ontario, 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
Ontario, California
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
2.44 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
12.48 μg/m³
0
55
155
255
425
605+
36.11 ppb
0
55
71
86
201
201+
0.37 ppb
0
36
76
186
605
1005+
24.39 ppb
0
54
101
361
1250
2050+
0.28 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Ontario, California
Ontario, California
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AQI 33
Good
2.72μg/m³
PM2.5
11.55μg/m³
PM10
35.86ppb
O3
0.37ppb
SO2
21.81ppb
NO2
0.28ppm
CO
AQI 33
Good
2.76μg/m³
PM2.5
11.37μg/m³
PM10
36.03ppb
O3
0.37ppb
SO2
20.39ppb
NO2
0.28ppm
CO
AQI 33
Good
2.51μg/m³
PM2.5
11.98μg/m³
PM10
36.09ppb
O3
0.37ppb
SO2
22.86ppb
NO2
0.28ppm
CO
AQI 33
Good
2.97μg/m³
PM2.5
10.91μg/m³
PM10
35.70ppb
O3
0.38ppb
SO2
20.78ppb
NO2
0.28ppm
CO
AQI 38
Good
2.16μg/m³
PM2.5
8.74μg/m³
PM10
40.82ppb
O3
0.36ppb
SO2
20.45ppb
NO2
0.29ppm
CO
AQI 33
Good
3.11μg/m³
PM2.5
10.58μg/m³
PM10
36.30ppb
O3
0.36ppb
SO2
14.96ppb
NO2
0.29ppm
CO
The air quality data for California, USA is gathered from reliable sources such as satellites and monitoring stations, adhering to US EPA guidelines. With the help of advanced algorithms and machine learning, factors like traffic and population density are analyzed to deliver accurate and dependable results.
Source: Ambee Data Sources
Air quality updates for Ontario, California are available every hour.
Ontario, California experienced its worst air quality at 02:00:00, 2026-10-22.
The best air quality in Ontario, California was observed at 02:00:00 on 2026-10-22.
The air quality in Ontario, California right now is Good, with an AQI of 33.
In Ontario, California, O3 is the most frequently found pollutant.
When air quality in Ontario, California is compromised, staying indoors and wearing a mask can reduce health risks.
Ontario, California currently has a PM2.5 concentration of 2.439 μg/m3.
Ontario, California currently has a PM10 concentration of 12.48 μg/m3.
The current carbon monoxide (CO) level in Ontario, California is 0.284 ppm.
The current sulfur dioxide (SO2) concentration in Ontario, California is 0.37 ppb.
Ontario, California currently has an ozone (O3) concentration of 36.114 ppm.
The current level of nitrogen dioxide (NO2) in Ontario, California is 24.391 ppb.
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