SmogRank / United Kingdom / England / Middlesbrough

Middlesbrough, month by month

Middlesbrough has a measured daily mean on 815 days since 1 January 2023. Its worst month was March 2026, at 46 US AQI (8.3 µg/m³), 2,060th of 2,971 cities on that month's world ranking. Its cleanest was September 2025, at 20 US AQI (3.6 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 199)91 days measured
Jan42#1,617Feb32#2,490Mar46#2,060AprnoneMaynoneJunnoneJulnoneAugnoneSep1 dayOct18#2,632
2025too few days for a mean (a year needs 256)240 days measured
JannoneFebnoneMar2 daysApr37#2,106May31#2,135Jun21#2,423Jul26#2,689Aug22#2,816Sep20#3,000Oct27#2,137Nov10 daysDec26#2,777
202432 for the year266 days measured1,823rd of 2,097 in the world
Jan34#1,769Feb27#2,173Mar40#950Apr20 daysMay46#1,238Jun27#2,267Jul23#2,429Aug29#1,850Sep41#1,033Oct33#1,526NovnoneDecnone
2023too few days for a mean (a year needs 256)218 days measured
Jan19 daysFeb1 dayMar11 daysApr37#1,107May18 daysJun16 daysJul18 daysAug20 daysSep33#1,808Oct16 daysNov36#1,566Dec34#1,773
Each square is a month's mean PM2.5 in US AQI from Middlesbrough'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 Middlesbrough 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

21 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 202510 of 30 days measured; a month needs 21. The others: 20 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 202420 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Oct 202316 of 31 days measured; a month needs 22. The others: 15 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 202316 of 30 days measured; a month needs 21. The others: 14 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 202311 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive.
Feb 20231 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 2 with under 18 hours of readings or readings that failed our checks.
Jan 202319 of 31 days measured; a month needs 22. The others: 7 missing from OpenAQ's archive, 5 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.

Middlesbrough's worst months

MonthUS AQIDays measuredWorld rank
March 2026 468.3 µg/m³25 of 312,060thof 2,971
May 2024 468.2 µg/m³31 of 311,238thof 2,684
January 2026 427.6 µg/m³31 of 311,617thof 2,617
September 2024 417.4 µg/m³30 of 301,033rdof 2,010
March 2024 407.2 µg/m³22 of 31950thof 1,698
April 2025 376.7 µg/m³28 of 302,106thof 2,951

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.

Middlesbrough's worst days

DayUS AQI
9 Sept 2023 8024.6 µg/m³
5 Mar 2026 7924.3 µg/m³
9 Mar 2026 7522.1 µg/m³
6 Mar 2026 7521.9 µg/m³
11 Mar 2024 7421.7 µg/m³
7 Sept 2024 7220.4 µg/m³
6 Nov 2023 7119.6 µg/m³
8 Sept 2023 7019.3 µg/m³
23 Jan 2023 6919.0 µg/m³
11 Jun 2023 6919.0 µg/m³

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, Middlesbrough, 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/middlesbrough/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.

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

Updated 2026-10-12 17:07 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).