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)
23
Good
Welwyn Garden City, Hertfordshire
Last updated: ... (Local time)
Good
Fine
Moderate
Poor
Very poor
Hazardous
2.33 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
7.91 μg/m³
0
55
155
255
425
605+
25.45 ppb
0
55
71
86
201
201+
0.38 ppb
0
36
76
186
605
1005+
1.66 ppb
0
54
101
361
1250
2050+
0.20 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Moderate
Welwyn Garden City, Hertfordshire
Welwyn Garden City, Hertfordshire
Scroll To Air Quality MapLoading...
AQI 33
Good
5.92μg/m³
PM2.5
15.30μg/m³
PM10
22.16ppb
O3
0.42ppb
SO2
6.30ppb
NO2
0.36ppm
CO
AQI 27
Good
4.58μg/m³
PM2.5
14.92μg/m³
PM10
22.22ppb
O3
0.43ppb
SO2
6.11ppb
NO2
0.36ppm
CO
AQI 27
Good
5.30μg/m³
PM2.5
12.75μg/m³
PM10
21.65ppb
O3
0.42ppb
SO2
4.39ppb
NO2
0.36ppm
CO
AQI 22
Good
4.02μg/m³
PM2.5
9.14μg/m³
PM10
23.12ppb
O3
0.40ppb
SO2
7.44ppb
NO2
0.36ppm
CO
AQI 27
Good
5.35μg/m³
PM2.5
9.98μg/m³
PM10
21.67ppb
O3
0.43ppb
SO2
3.75ppb
NO2
0.36ppm
CO
AQI 22
Good
4.39μg/m³
PM2.5
11.74μg/m³
PM10
22.31ppb
O3
0.41ppb
SO2
7.04ppb
NO2
0.36ppm
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 2025-09-16.
In the last 24 hrs, the best air quality in Welwyn Garden City, Hertfordshire was observed at 12:00:00 on 2025-09-17.
The current air quality in Welwyn Garden City, Hertfordshire is 27, 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 5.232 μg/m3.
The current PM10 concentration at Welwyn Garden City, Hertfordshire is 10.047 μg/m3.
The current carbon monoxide (CO) concentration at Welwyn Garden City, Hertfordshire is 0.37 ppm.
The current sulfur dioxide (SO2) concentration at Welwyn Garden City, Hertfordshire is 0.434 ppb.
The current ozone (O3) concentration at Welwyn Garden City, Hertfordshire is 19.884 ppm.
The current nitrogen dioxide (NO2) concentration at Welwyn Garden City, Hertfordshire is 6.48 ppb.
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