Stay updated with real-time air quality in Welwyn Garden City, 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)
60
Moderate
Welwyn Garden City, Hertfordshire
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
14.06 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
33.26 μg/m³
0
55
155
255
425
605+
9.74 ppb
0
55
71
86
201
201+
1.15 ppb
0
36
76
186
605
1005+
22.82 ppb
0
54
101
361
1250
2050+
0.06 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Welwyn Garden City, Hertfordshire
Welwyn Garden City, Hertfordshire
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AQI 49
Good
9.28μg/m³
PM2.5
14.36μg/m³
PM10
10.70ppb
O3
1.57ppb
SO2
18.21ppb
NO2
0.05ppm
CO
AQI 52
Moderate
10.22μg/m³
PM2.5
14.36μg/m³
PM10
10.37ppb
O3
1.21ppb
SO2
20.71ppb
NO2
0.05ppm
CO
AQI 38
Good
7.25μg/m³
PM2.5
10.88μg/m³
PM10
12.73ppb
O3
1.22ppb
SO2
17.17ppb
NO2
0.07ppm
CO
AQI 44
Good
8.32μg/m³
PM2.5
14.70μg/m³
PM10
10.64ppb
O3
0.96ppb
SO2
24.17ppb
NO2
0.04ppm
CO
AQI 38
Good
7.38μg/m³
PM2.5
10.87μg/m³
PM10
15.11ppb
O3
1.19ppb
SO2
15.11ppb
NO2
0.08ppm
CO
AQI 38
Good
6.99μg/m³
PM2.5
14.89μg/m³
PM10
9.98ppb
O3
0.86ppb
SO2
22.93ppb
NO2
0.02ppm
CO
Air quality data and pollutant measurements for Hertfordshire, UK adhere to strict US EPA standards. The data is collected from multiple reliable sources, including satellites and ground-based monitoring stations. This data is further analyzed and enhanced using machine learning and advanced algorithms that factor in elements such as traffic and population density, ensuring accurate and reliable results.
Source: Ambee Data Sources
The air quality for Welwyn Garden City, Hertfordshire is updated every hour.
The worst air quality in Welwyn Garden City, Hertfordshire in the last 24 hours was observed at 08:00:00 on 2025-12-05.
In the last 24 hrs, the best air quality in Welwyn Garden City, Hertfordshire was observed at 10:00:00 on 2025-12-04.
The current air quality in Welwyn Garden City, Hertfordshire is 38, categorized as Good based on real-time data.
The most common pollutant in Welwyn Garden City, Hertfordshire is PM2.5.
If the air quality in Welwyn Garden City, Hertfordshire is poor, consider staying indoors and wearing a mask to protect yourself.
The current PM2.5 concentration at Welwyn Garden City, Hertfordshire is 6.55 μg/m3.
The current PM10 concentration at Welwyn Garden City, Hertfordshire is 12.516 μg/m3.
The current carbon monoxide (CO) concentration at Welwyn Garden City, Hertfordshire is 0.066 ppm.
The current sulfur dioxide (SO2) concentration at Welwyn Garden City, Hertfordshire is 1.263 ppb.
The current ozone (O3) concentration at Welwyn Garden City, Hertfordshire is 11.952 ppm.
The current nitrogen dioxide (NO2) concentration at Welwyn Garden City, Hertfordshire is 18.041 ppb.
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