Stay updated with real-time air quality in Letchworth, 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)
44
Good
Letchworth, Hertfordshire
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
8.31 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
25.80 μg/m³
0
55
155
255
425
605+
13.29 ppb
0
55
71
86
201
201+
0.86 ppb
0
36
76
186
605
1005+
13.81 ppb
0
54
101
361
1250
2050+
0.80 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Moderate
Letchworth, Hertfordshire
Letchworth, Hertfordshire
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AQI 27
Good
5.45μg/m³
PM2.5
29.17μg/m³
PM10
22.59ppb
O3
0.95ppb
SO2
14.16ppb
NO2
1.01ppm
CO
AQI 27
Good
5.45μg/m³
PM2.5
29.17μg/m³
PM10
22.59ppb
O3
0.95ppb
SO2
14.16ppb
NO2
1.01ppm
CO
AQI 44
Good
8.13μg/m³
PM2.5
13.68μg/m³
PM10
19.33ppb
O3
0.95ppb
SO2
22.80ppb
NO2
1.01ppm
CO
AQI 44
Good
8.13μg/m³
PM2.5
13.68μg/m³
PM10
19.33ppb
O3
0.95ppb
SO2
22.80ppb
NO2
1.01ppm
CO
AQI 27
Good
5.45μg/m³
PM2.5
29.17μg/m³
PM10
22.59ppb
O3
0.95ppb
SO2
14.16ppb
NO2
1.01ppm
CO
AQI 27
Good
5.33μg/m³
PM2.5
26.59μg/m³
PM10
26.55ppb
O3
0.95ppb
SO2
15.43ppb
NO2
1.01ppm
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 Letchworth, Hertfordshire is updated every hour for accuracy.
In the past 24 hours, the air quality in Letchworth, Hertfordshire was at its worst at 02:00:00 on 2026-02-11.
In the last 24 hours, the best air quality in Letchworth, Hertfordshire was observed at 11:00:00 on 2026-02-11.
As of now, the AQI in Letchworth, Hertfordshire is 44, indicating Good conditions.
Letchworth, Hertfordshire air has the highest levels of PM2.5.
Poor air quality in Letchworth, Hertfordshire means it's advisable to stay indoors and wear a mask for your protection.
PM2.5 levels in Letchworth, Hertfordshire are currently 8.313 μg/m3.
The PM10 concentration in Letchworth, Hertfordshire is 25.797 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Letchworth, Hertfordshire is 0.803 ppm.
Currently, Letchworth, Hertfordshire has a sulfur dioxide (SO2) concentration of 0.864 ppb.
The current ozone (O3) level in Letchworth, Hertfordshire at the moment is 13.286 ppm.
Nitrogen dioxide (NO2) level in Letchworth, Hertfordshire at the moment is 13.815 ppb.
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