SmogRank / United Kingdom / England / Bristol

Bristol, month by month

Bristol has a measured daily mean on 718 days since 11 May 2023. Its worst month was March 2026, at 53 US AQI (10.3 µg/m³), 1,593rd of 2,971 cities on that month's world ranking. Its cleanest was August 2023, at 24 US AQI (4.4 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 199)90 days measured
Jan45#1,462Feb33#2,427Mar53#1,593AprnoneMaynoneJunnoneJulnoneAugnoneSep1 dayOct24#2,424
2025too few days for a mean (a year needs 256)231 days measured
JannoneFebnoneMar2 daysApr51#1,410May44#1,352Jun37#2,078Jul32#2,378Aug37#2,290Sep28#2,600Oct21 daysNov12 daysDec41#2,030
2024too few days for a mean (a year needs 257)247 days measured
Jan19 daysFeb32#1,929Mar38#1,039Apr18 daysMay43#1,433Jun39#1,661Jul20 daysAug41#1,460Sep41#1,033Oct38#1,197NovnoneDecnone
2023too few days for a mean (a year needs 256)150 days measured
JanFebMarAprMay12 daysJun17 daysJul13 daysAug24#1,885Sep46#1,008Oct15 daysNov47#1,028Dec42#1,368
Each square is a month's mean PM2.5 in US AQI from Bristol'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 Bristol 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

20 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 202521 of 31 days measured; a month needs 22. The others: 10 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.
Jul 202420 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks.
Apr 202418 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks.
Jan 202419 of 31 days measured; a month needs 22. The others: 12 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.
Jul 202313 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 17 with under 18 hours of readings or readings that failed our checks.
Jun 202317 of 30 days measured; a month needs 21. The others: 13 with under 18 hours of readings or readings that failed our checks.
May 202312 of 31 days measured; a month needs 22. The others: 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.

Bristol's worst months

MonthUS AQIDays measuredWorld rankEpisode
March 2026 5310.3 µg/m³26 of 311,593rdof 2,971Europe, 1 to 12 March 2026
April 2025 519.2 µg/m³28 of 301,410thof 2,951–
November 2023 478.4 µg/m³22 of 301,028thof 2,243France, Belgium and 2 more countries, November and December 2023
September 2023 468.3 µg/m³23 of 301,008thof 2,176–
January 2026 458.1 µg/m³27 of 311,462ndof 2,617–
May 2025 448.0 µg/m³27 of 311,352ndof 2,826–

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.

Bristol's worst days

DayUS AQIEpisode
9 Mar 2026 8828.9 µg/m³Europe, 1 to 12 March 2026
2 Dec 2023 8728.5 µg/m³France, Belgium and 2 more countries, November and December 2023
11 Jun 2023 7823.5 µg/m³–
21 Mar 2026 7823.4 µg/m³–
5 Mar 2026 7622.3 µg/m³Europe, 1 to 12 March 2026
20 Mar 2026 7320.8 µg/m³–
26 Nov 2023 7220.2 µg/m³–
6 Jan 2026 7119.8 µg/m³–
20 Sept 2024 7119.6 µg/m³–
31 Dec 2025 7019.3 µg/m³–

Daily means, the highest since 11 May 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, Bristol, United Kingdom, 11 May 2023 – 11 Oct 2026. Monitor data from UK-AIR (Defra), read from the publisher; sources listed at smogrank.com/sources. smogrank.com/gb/bristol/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.

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

Updated 2026-10-12 21:07 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).