Stay updated with real-time air quality in Harpenden, Hertfordshire 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)
22
Good
Harpenden, Hertfordshire
Last updated: ... (Local time)
Good
Fine
Moderate
Poor
Very poor
Hazardous
4.41 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
14.07 μg/m³
0
55
155
255
425
605+
23.31 ppb
0
55
71
86
201
201+
0.85 ppb
0
36
76
186
605
1005+
8.90 ppb
0
54
101
361
1250
2050+
0.24 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
High
Harpenden, Hertfordshire
Harpenden, Hertfordshire
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AQI 18
Good
3.46μg/m³
PM2.5
10.48μg/m³
PM10
18.89ppb
O3
0.56ppb
SO2
11.50ppb
NO2
0.01ppm
CO
AQI 22
Good
3.62μg/m³
PM2.5
12.78μg/m³
PM10
18.68ppb
O3
0.72ppb
SO2
7.22ppb
NO2
0.01ppm
CO
AQI 22
Good
3.77μg/m³
PM2.5
12.04μg/m³
PM10
16.96ppb
O3
0.73ppb
SO2
8.16ppb
NO2
0.01ppm
CO
AQI 16
Good
3.02μg/m³
PM2.5
11.57μg/m³
PM10
16.98ppb
O3
0.72ppb
SO2
9.25ppb
NO2
0.01ppm
CO
AQI 22
Good
3.62μg/m³
PM2.5
12.78μg/m³
PM10
18.68ppb
O3
0.72ppb
SO2
7.22ppb
NO2
0.01ppm
CO
AQI 22
Good
3.96μg/m³
PM2.5
17.34μg/m³
PM10
18.51ppb
O3
0.71ppb
SO2
14.37ppb
NO2
0.01ppm
CO
Air quality and pollutant data for Hertfordshire, UK are sourced from ground-based monitors and satellites, adhering to US EPA standards. Machine learning and advanced algorithms enhance the data by incorporating local variables like traffic and population density, ensuring high accuracy and dependability.
Source: Ambee Data Sources
The air quality information for Harpenden, Hertfordshire is updated every hour for accuracy.
In the past 24 hours, the air quality in Harpenden, Hertfordshire was at its worst at 10:00:00 on 2025-07-21.
In the last 24 hours, the best air quality in Harpenden, Hertfordshire was observed at 07:00:00 on 2025-07-21.
As of now, the AQI in Harpenden, Hertfordshire is 22, indicating Good conditions.
Harpenden, Hertfordshire air has the highest levels of PM2.5.
Poor air quality in Harpenden, Hertfordshire means it's advisable to stay indoors and wear a mask for your protection.
PM2.5 levels in Harpenden, Hertfordshire are currently 3.85 μg/m3.
The PM10 concentration in Harpenden, Hertfordshire is 13.806 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Harpenden, Hertfordshire is 0.013 ppm.
Currently, Harpenden, Hertfordshire has a sulfur dioxide (SO2) concentration of 0.726 ppb.
The current ozone (O3) level in Harpenden, Hertfordshire at the moment is 17.193 ppm.
Nitrogen dioxide (NO2) level in Harpenden, Hertfordshire at the moment is 11.218 ppb.
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