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)
37
Good
Half Moon Bay, California
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
2.25 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
8.97 μg/m³
0
55
155
255
425
605+
40.29 ppb
0
55
71
86
201
201+
0.47 ppb
0
36
76
186
605
1005+
5.97 ppb
0
54
101
361
1250
2050+
0.17 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
High
Half Moon Bay, California
Half Moon Bay, California
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AQI 34
Good
2.72μg/m³
PM2.5
11.21μg/m³
PM10
36.69ppb
O3
0.50ppb
SO2
6.74ppb
NO2
0.17ppm
CO
AQI 33
Good
2.73μg/m³
PM2.5
11.10μg/m³
PM10
35.60ppb
O3
0.51ppb
SO2
6.65ppb
NO2
0.17ppm
CO
AQI 33
Good
2.88μg/m³
PM2.5
11.84μg/m³
PM10
36.01ppb
O3
0.50ppb
SO2
6.83ppb
NO2
0.17ppm
CO
AQI 33
Good
2.31μg/m³
PM2.5
9.41μg/m³
PM10
36.16ppb
O3
0.51ppb
SO2
6.41ppb
NO2
0.17ppm
CO
AQI 33
Good
2.91μg/m³
PM2.5
12.09μg/m³
PM10
36.39ppb
O3
0.50ppb
SO2
6.94ppb
NO2
0.17ppm
CO
AQI 33
Good
2.20μg/m³
PM2.5
8.88μg/m³
PM10
35.81ppb
O3
0.55ppb
SO2
6.49ppb
NO2
0.17ppm
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 02:00:00, 2026-04-17.
The best air quality in Half Moon Bay, California was observed at 04:00:00 on 2026-04-16.
The air quality in Half Moon Bay, California right now is Good, with an AQI of 37.
In Half Moon Bay, California, O3 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 2.246 μg/m3.
Half Moon Bay, California currently has a PM10 concentration of 8.972 μg/m3.
The current carbon monoxide (CO) level in Half Moon Bay, California is 0.169 ppm.
The current sulfur dioxide (SO2) concentration in Half Moon Bay, California is 0.467 ppb.
Half Moon Bay, California currently has an ozone (O3) concentration of 40.286 ppm.
The current level of nitrogen dioxide (NO2) in Half Moon Bay, California is 5.969 ppb.
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