Stay updated with real-time air quality in Half Moon Bay, 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)
44
Good
Half Moon Bay, California
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
8.00 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
34.35 μg/m³
0
55
155
255
425
605+
30.42 ppb
0
55
71
86
201
201+
0.42 ppb
0
36
76
186
605
1005+
4.33 ppb
0
54
101
361
1250
2050+
0.31 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Half Moon Bay, California
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AQI 54
Moderate
10.69μg/m³
PM2.5
40.16μg/m³
PM10
32.69ppb
O3
0.29ppb
SO2
2.98ppb
NO2
0.28ppm
CO
AQI 52
Moderate
10.38μg/m³
PM2.5
39.98μg/m³
PM10
32.57ppb
O3
0.28ppb
SO2
2.66ppb
NO2
0.28ppm
CO
AQI 56
Moderate
11.67μg/m³
PM2.5
50.33μg/m³
PM10
32.68ppb
O3
0.30ppb
SO2
2.90ppb
NO2
0.28ppm
CO
AQI 52
Moderate
10.02μg/m³
PM2.5
43.81μg/m³
PM10
27.23ppb
O3
0.27ppb
SO2
6.71ppb
NO2
0.28ppm
CO
AQI 56
Moderate
11.67μg/m³
PM2.5
50.33μg/m³
PM10
32.68ppb
O3
0.30ppb
SO2
2.90ppb
NO2
0.28ppm
CO
AQI 49
Good
9.13μg/m³
PM2.5
39.84μg/m³
PM10
25.17ppb
O3
0.27ppb
SO2
7.24ppb
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 Half Moon Bay, California are available every hour.
Half Moon Bay, California experienced its worst air quality at 08:00:00, 2026-03-10.
The best air quality in Half Moon Bay, California was observed at 11:00:00 on 2026-03-09.
The air quality in Half Moon Bay, California right now is Good, with an AQI of 44.
In Half Moon Bay, California, PM2.5 is the most frequently found pollutant.
When air quality in Half Moon Bay, California is compromised, staying indoors and wearing a mask can reduce health risks.
Half Moon Bay, California currently has a PM2.5 concentration of 8.048 μg/m3.
Half Moon Bay, California currently has a PM10 concentration of 31.896 μg/m3.
The current carbon monoxide (CO) level in Half Moon Bay, California is 0.284 ppm.
The current sulfur dioxide (SO2) concentration in Half Moon Bay, California is 0.266 ppb.
Half Moon Bay, California currently has an ozone (O3) concentration of 31.786 ppm.
The current level of nitrogen dioxide (NO2) in Half Moon Bay, California is 3.938 ppb.
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