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)
31
Good
Letchworth, Hertfordshire
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
4.33 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
19.34 μg/m³
0
55
155
255
425
605+
32.51 ppb
0
55
71
86
201
201+
0.55 ppb
0
36
76
186
605
1005+
5.34 ppb
0
54
101
361
1250
2050+
0.31 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Letchworth, Hertfordshire
Letchworth, Hertfordshire
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AQI 30
Good
4.30μg/m³
PM2.5
11.34μg/m³
PM10
32.44ppb
O3
0.54ppb
SO2
5.35ppb
NO2
0.31ppm
CO
AQI 30
Good
4.30μg/m³
PM2.5
11.34μg/m³
PM10
32.44ppb
O3
0.54ppb
SO2
5.35ppb
NO2
0.31ppm
CO
AQI 31
Good
4.33μg/m³
PM2.5
19.34μg/m³
PM10
32.51ppb
O3
0.55ppb
SO2
5.34ppb
NO2
0.31ppm
CO
AQI 31
Good
4.33μg/m³
PM2.5
19.34μg/m³
PM10
32.51ppb
O3
0.55ppb
SO2
5.34ppb
NO2
0.31ppm
CO
AQI 30
Good
4.30μg/m³
PM2.5
11.34μg/m³
PM10
32.44ppb
O3
0.54ppb
SO2
5.35ppb
NO2
0.31ppm
CO
AQI 29
Good
3.92μg/m³
PM2.5
13.20μg/m³
PM10
31.07ppb
O3
0.52ppb
SO2
6.46ppb
NO2
0.31ppm
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 10:00:00 on 2026-09-28.
In the last 24 hours, the best air quality in Letchworth, Hertfordshire was observed at 05:00:00 on 2026-09-28.
As of now, the AQI in Letchworth, Hertfordshire is 31, indicating Good conditions.
Letchworth, Hertfordshire air has the highest levels of O3.
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 4.334 μg/m3.
The PM10 concentration in Letchworth, Hertfordshire is 19.336 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Letchworth, Hertfordshire is 0.312 ppm.
Currently, Letchworth, Hertfordshire has a sulfur dioxide (SO2) concentration of 0.545 ppb.
The current ozone (O3) level in Letchworth, Hertfordshire at the moment is 32.512 ppm.
Nitrogen dioxide (NO2) level in Letchworth, Hertfordshire at the moment is 5.34 ppb.
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