SmogRank / Germany / North Rhine-Westphalia / Roetgen

Roetgen, month by month

Roetgen has a measured daily mean on 529 days since 14 February 2023. Its worst month was June 2023, at 61 US AQI (14.2 µg/m³), 426th of 1,603 cities on that month's world ranking. Its cleanest was September 2025, at 19 US AQI (3.5 µg/m³).

Every month since 2023

202633 so far241 days measured2,503rd of 2,791 in the world
Jan37#1,901Feb26#2,634Mar50#1,881Apr31#2,368May28#2,304Jun16 daysJul34#2,396Aug29#2,690Sep17 daysOct25#2,322
2025too few days for a mean (a year needs 256)179 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJun6 daysJul28#2,595Aug33#2,535Sep19#3,013Oct30#1,866Nov22#2,582Dec28#2,695
2024too few days for a mean (a year needs 257)0 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
2023too few days for a mean (a year needs 256)109 days measured
JanFeb2 daysMar11 daysApr43#882May51#604Jun61#426Jul12 daysAugnoneSepnoneOctnoneNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Roetgen'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 Roetgen 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

28 months
MonthWhy
Sep 202617 of 30 days measured; a month needs 21. The others: 13 with readings for part of the day (a day needs 18 hours).
Jun 202616 of 30 days measured; a month needs 21. The others: 7 with no readings from the monitor, 7 with readings for part of the day (a day needs 18 hours).
Jun 20256 of 30 days measured; a month needs 21. The others: 3 with readings for part of the day (a day needs 18 hours), 21 with under 18 hours of readings or readings that failed our checks.
May 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 2025No day measured. The others: 31 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.
Nov 2024No day measured.
Oct 2024No day measured.
Sep 2024No day measured.
Aug 2024No day measured.
Jul 2024No day measured.
Jun 2024No day measured.
May 2024No day measured.
Apr 2024No day measured.
Mar 2024No day measured.
Feb 2024No day measured.
Jan 2024No day measured.
Dec 2023No day measured. The others: 31 with no readings from the monitor.
Nov 2023No day measured. The others: 30 with no readings from the monitor.
Oct 2023No day measured. The others: 31 with no readings from the monitor.
Sep 2023No day measured. The others: 30 with no readings from the monitor.
Aug 2023No day measured. The others: 31 with no readings from the monitor.
Jul 202312 of 31 days measured; a month needs 22. The others: 17 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours), 1 missing from OpenAQ's archive.
Mar 202311 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive.
Feb 20232 of 28 days measured; a month needs 20. The others: 13 missing from OpenAQ's archive.

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

Roetgen's worst months

MonthUS AQIDays measuredWorld rankEpisode
June 2023 6114.2 µg/m³28 of 30426thof 1,603United Kingdom, Belgium and 2 more countries, June 2023
May 2023 519.2 µg/m³31 of 31604thof 1,600Europe, May 2023
March 2026 509.0 µg/m³31 of 311,881stof 2,971–
April 2023 437.7 µg/m³25 of 30882ndof 1,622–
January 2026 376.7 µg/m³28 of 311,901stof 2,617–
July 2026 346.1 µg/m³29 of 312,396thof 2,784–

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.

Roetgen's worst days

DayUS AQIEpisode
15 Jun 2023 12846.3 µg/m³–
16 Jun 2023 12645.5 µg/m³–
14 Jun 2023 8728.5 µg/m³–
6 Jun 2023 8527.1 µg/m³–
22 May 2023 8326.1 µg/m³Europe, May 2023
12 Jun 2023 8125.2 µg/m³United Kingdom, Belgium and 2 more countries, June 2023
26 Jan 2026 7723.2 µg/m³–
20 Mar 2026 7723.0 µg/m³–
24 Mar 2026 7622.7 µg/m³–
13 Jun 2023 7421.4 µg/m³–

Daily means, the highest since 14 Feb 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, Roetgen, Germany, 14 Feb 2023 – 10 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/de/roetgen/history (accessed 12 Oct 2026).

Download chart (PNG)

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.

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

Updated 2026-10-12 18:07 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).