Halesworth vs Norwich: PM2.5 compared

Over the last year, Norwich's air was 18% more polluted than Halesworth's: PM2.5 averaged 9.3 µg/m³ against 7.9, on the 125 days both cities were measured. Norwich had the dirtier air on 104 of those days, Halesworth on 18. Norwich was over the WHO's daily guideline of 15 µg/m³ on 19 of them, Halesworth on 11.

Right now

Halesworth#675on the 24-hour board of 738, at 13 US AQI (2.4 µg/m³)

Norwich#639on the 24-hour board of 738, at 14 US AQI (2.6 µg/m³)

The last year, day by day

Halesworth

Norwich

Each city's daily mean from 8 Oct 2025 to 7 Oct 2026, one stripe a day, coloured by band. A blank stripe is a day without a daily mean.

Month by month

Monthly means in µg/m³ over the days both cities were measured. Solid: Halesworth. Faded: Norwich. A month shows once both share 10 such days. Dashed line: the WHO daily guideline, 15 µg/m³.

Year by year

Year	Halesworth	Norwich	Days both measured	Days Halesworth was worse
2026 so far	52	55	76	16
2025	35	37	191	50
2024	37	40	227	59

Means in US AQI over the days both cities were measured that year; a year shows once they share 30 such days.

Each city's worst days

Halesworth

24 Mar 20268929.3 µg/m³
26 Jan 20268829.0 µg/m³
6 Mar 20268728.4 µg/m³

Norwich

26 Jan 20269935.0 µg/m³
6 Feb 20269432.1 µg/m³
3 Feb 20268728.4 µg/m³

Daily means in US AQI, with µg/m³ beside them, since the index stops at its top value, over the days both cities were measured in the last year. Each date opens that day's world board.

Compare either city with another

Halesworth

Side by side with London (United Kingdom's worst on 30 days), Gujranwala (the world's worst on 30 days).

Norwich

Side by side with London (United Kingdom's worst on 30 days), Gujranwala (the world's worst on 30 days).

Use this page

SmogRank, PM2.5 daily means compared, Halesworth and Norwich, 8 Oct 2025 – 7 Oct 2026, smogrank.com/compare/gb-halesworth/gb-norwich (accessed 8 Oct 2026).

You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

The same rules as every SmogRank figure: reference monitors first, and a day counts with 18 measured hours. How we measure.

Updated 2026-10-08 20:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); Love My Air (City and County of Denver), no reuse terms published (why we use them).