SmogRank / United Kingdom / England / Norwich

Norwich, month by month

Norwich has a measured daily mean on 761 days since 1 January 2023. Its worst month was March 2026, at 55 US AQI (11.0 µg/m³), 1,423rd of 2,971 cities on that month's world ranking. Its cleanest was July 2024, at 28 US AQI (5.0 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 199)94 days measured
Jan53#1,054Feb54#1,230Mar55#1,423AprnoneMaynoneJunnoneJulnoneAugnoneSep1 dayOct21#2,557
2025too few days for a mean (a year needs 256)207 days measured
JannoneFebnoneMar2 daysApr51#1,410May35#1,828Jun32#2,206Jul32#2,420Aug34#2,476Sep15 daysOct20 daysNov12 daysDec40#2,090
2024too few days for a mean (a year needs 257)255 days measured
Jan42#1,376Feb34#1,803Mar52#495Apr16 daysMay51#906Jun32#2,080Jul28#2,263Aug33#1,752Sep50#595Oct36#1,342NovnoneDecnone
2023too few days for a mean (a year needs 256)205 days measured
Jan16 daysFeb3 daysMar8 daysApr53#396May18 daysJun13 daysJul18 daysAug20 daysSep53#592Oct15 daysNov41#1,350Dec34#1,773
Each square is a month's mean PM2.5 in US AQI from Norwich's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Norwich marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Months without a mean, and why

23 months
MonthWhy
Sep 20261 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks.
Aug 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jun 2026No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 2026No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Nov 202512 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks.
Oct 202520 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks.
Sep 202515 of 30 days measured; a month needs 21. The others: 15 with under 18 hours of readings or readings that failed our checks.
Mar 20252 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks.
Feb 2025No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks.
Jan 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Dec 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Apr 202416 of 30 days measured; a month needs 21. The others: 14 with under 18 hours of readings or readings that failed our checks.
Oct 202315 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Aug 202320 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks.
Jul 202318 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 12 with under 18 hours of readings or readings that failed our checks.
Jun 202313 of 30 days measured; a month needs 21. The others: 17 with under 18 hours of readings or readings that failed our checks.
May 202318 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Mar 20238 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive, 3 with under 18 hours of readings or readings that failed our checks.
Feb 20233 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive.
Jan 202316 of 31 days measured; a month needs 22. The others: 6 missing from OpenAQ's archive, 9 with under 18 hours of readings or readings that failed our checks.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Norwich's worst months

MonthUS AQIDays measuredWorld rankEpisode
March 2026 5511.0 µg/m³25 of 311,423rdof 2,971Europe, 18 to 25 March 2026
Europe, 1 to 12 March 2026
February 2026 5410.8 µg/m³26 of 281,230thof 2,866Europe, January and February 2026
April 2023 5310.4 µg/m³21 of 30396thof 1,622Germany, The Netherlands and United Kingdom, April 2023
January 2026 5310.3 µg/m³31 of 311,054thof 2,617Europe, January and February 2026
September 2023 5310.0 µg/m³21 of 30592ndof 2,176United Kingdom, Belgium and 2 more countries, September 2023
March 2024 529.5 µg/m³22 of 31495thof 1,698United Kingdom and The Netherlands, March 2024

Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.

Norwich's worst days

DayUS AQIEpisode
15 Feb 2023 10336.3 µg/m³Europe, 6 to 25 February 2023
26 Jan 2026 9935.0 µg/m³Europe, January and February 2026
11 Mar 2024 9834.4 µg/m³United Kingdom and The Netherlands, March 2024
6 Feb 2026 9432.1 µg/m³Europe, January and February 2026
9 Sept 2023 9030.1 µg/m³United Kingdom, Belgium and 2 more countries, September 2023
14 Feb 2023 8929.5 µg/m³Europe, 6 to 25 February 2023
3 Feb 2026 8728.4 µg/m³Europe, January and February 2026
6 Mar 2026 8627.8 µg/m³Europe, 1 to 12 March 2026
10 Apr 2023 8527.4 µg/m³Germany, The Netherlands and United Kingdom, April 2023
5 Feb 2026 8326.3 µg/m³Europe, January and February 2026

Daily means, the highest since 1 Jan 2023; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.

Use this history

SmogRank, PM2.5 monthly and daily means, Norwich, United Kingdom, 1 Jan 2023 – 11 Oct 2026. Monitor data from UK-AIR (Defra), read from the publisher; sources listed at smogrank.com/sources. smogrank.com/gb/norwich/history (accessed 12 Oct 2026).

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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.

Norwich now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 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 low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).