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)
32
Good
Harpenden, Hertfordshire
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
5.33 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
35.30 μg/m³
0
55
155
255
425
605+
21.62 ppb
0
55
71
86
201
201+
1.53 ppb
0
36
76
186
605
1005+
4.74 ppb
0
54
101
361
1250
2050+
0.30 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Moderate
Harpenden, Hertfordshire
Harpenden, Hertfordshire
Scroll To Air Quality MapLoading...
AQI 44
Good
8.12μg/m³
PM2.5
21.68μg/m³
PM10
19.11ppb
O3
0.48ppb
SO2
19.89ppb
NO2
0.01ppm
CO
AQI 49
Good
9.42μg/m³
PM2.5
14.92μg/m³
PM10
16.89ppb
O3
0.75ppb
SO2
13.17ppb
NO2
0.01ppm
CO
AQI 38
Good
7.46μg/m³
PM2.5
32.08μg/m³
PM10
16.36ppb
O3
0.76ppb
SO2
18.97ppb
NO2
0.01ppm
CO
AQI 38
Good
7.46μg/m³
PM2.5
21.12μg/m³
PM10
16.54ppb
O3
0.58ppb
SO2
13.17ppb
NO2
0.01ppm
CO
AQI 49
Good
9.42μg/m³
PM2.5
14.92μg/m³
PM10
16.89ppb
O3
0.75ppb
SO2
13.17ppb
NO2
0.01ppm
CO
AQI 49
Good
8.82μg/m³
PM2.5
38.97μg/m³
PM10
16.64ppb
O3
0.74ppb
SO2
24.06ppb
NO2
0.02ppm
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 07:00:00 on 2025-11-06.
In the last 24 hours, the best air quality in Harpenden, Hertfordshire was observed at 05:00:00 on 2025-11-06.
As of now, the AQI in Harpenden, Hertfordshire is 49, 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 9.228 μg/m3.
The PM10 concentration in Harpenden, Hertfordshire is 21.84 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Harpenden, Hertfordshire is 0.019 ppm.
Currently, Harpenden, Hertfordshire has a sulfur dioxide (SO2) concentration of 1 ppb.
The current ozone (O3) level in Harpenden, Hertfordshire at the moment is 17.795 ppm.
Nitrogen dioxide (NO2) level in Harpenden, Hertfordshire at the moment is 15.461 ppb.
All Rights Reserved © Ambee Inc. 2025