SmogRank / Germany / North Rhine-Westphalia / Netphen

Netphen, month by month

Netphen has a measured daily mean on 857 days since 11 January 2023. Its worst month was February 2023, at 43 US AQI (7.8 µg/m³), 839th of 1,129 cities on that month's world ranking. Its cleanest was December 2024, at 17 US AQI (3.0 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 199)168 days measured
Jan17 daysFeb14 daysMar19 daysApr12 daysMay22#2,649Jun16 daysJul20 daysAug19 daysSep16 daysOct19#2,593
2025too few days for a mean (a year needs 256)203 days measured
Jan21#2,402Feb18 daysMar17 daysApr2 daysMay14 daysJun15 daysJul26#2,689Aug29#2,649Sep14 daysOct16 daysNov12 daysDec15 days
2024too few days for a mean (a year needs 257)253 days measured
Jan29#2,027Feb21#2,352Mar15 daysApr19#2,347May27#2,289Jun31#2,133Jul25#2,368Aug14 daysSepnoneOct10 daysNov23#2,450Dec17#2,560
2023too few days for a mean (a year needs 256)233 days measured
Jan7 daysFeb43#839Mar26#834Apr35#1,162May39#1,122Jun41#1,178Jul12 daysAugnoneSepnoneOct8 daysNov17#2,194Dec22#2,138
Each square is a month's mean PM2.5 in US AQI from Netphen'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 Netphen 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

26 months
MonthWhy
Sep 202616 of 30 days measured; a month needs 21. The others: 14 with readings for part of the day (a day needs 18 hours).
Aug 202619 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks.
Jul 202620 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks.
Jun 202616 of 30 days measured; a month needs 21. The others: 14 with under 18 hours of readings or readings that failed our checks.
Apr 202612 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks.
Mar 202619 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks.
Feb 202614 of 28 days measured; a month needs 20. The others: 14 with under 18 hours of readings or readings that failed our checks.
Jan 202617 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks.
Dec 202515 of 31 days measured; a month needs 22. The others: 16 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 202516 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Sep 202514 of 30 days measured; a month needs 21. The others: 16 with under 18 hours of readings or readings that failed our checks.
Jun 202515 of 30 days measured; a month needs 21. The others: 15 with under 18 hours of readings or readings that failed our checks.
May 202514 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Apr 20252 of 30 days measured; a month needs 21. The others: 28 with under 18 hours of readings or readings that failed our checks.
Mar 202517 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks.
Feb 202518 of 28 days measured; a month needs 20. The others: 10 with under 18 hours of readings or readings that failed our checks.
Oct 202410 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Sep 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Aug 202414 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Mar 202415 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Oct 20238 of 31 days measured; a month needs 22. The others: 23 with under 18 hours of readings or readings that failed our checks.
Sep 2023No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Aug 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 202312 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks.
Jan 20237 of 31 days measured; a month needs 22. The others: 14 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.

Netphen's worst months

MonthUS AQIDays measuredWorld rank
February 2023 437.8 µg/m³27 of 28839thof 1,129
June 2023 417.4 µg/m³29 of 301,178thof 1,603
May 2023 397.1 µg/m³29 of 311,122ndof 1,600
April 2023 356.3 µg/m³30 of 301,162ndof 1,622
June 2024 315.6 µg/m³26 of 302,133rdof 2,563
August 2025 295.3 µg/m³30 of 312,649thof 2,901

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.

Netphen's worst days

DayUS AQIEpisode
10 Feb 2025 10035.3 µg/m³Europe, 1 to 14 February 2025
11 Mar 2025 10035.3 µg/m³Germany, Poland and 25 more countries, March 2025
25 Jan 2026 9432.2 µg/m³Europe, January and February 2026
9 Feb 2025 8326.4 µg/m³Europe, 1 to 14 February 2025
10 Feb 2023 8024.6 µg/m³–
24 Jan 2026 7924.1 µg/m³Europe, January and February 2026
9 Mar 2025 7622.7 µg/m³Germany, Poland and 25 more countries, March 2025
13 Feb 2025 7622.3 µg/m³Europe, 1 to 14 February 2025
10 Mar 2025 7321.1 µg/m³Germany, Poland and 25 more countries, March 2025
9 Mar 2026 7119.6 µg/m³–

Daily means, the highest since 11 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, Netphen, Germany, 11 Jan 2023 – 10 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/de/netphen/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.

Netphen 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).