SmogRank / Belgium / Wallonia / Ans

Ans, month by month

Ans has a measured daily mean on 447 days since 1 February 2024. Its worst month was January 2026, at 48 US AQI (8.7 µg/m³), 1,313th of 2,617 cities on that month's world ranking. Its cleanest was August 2026, at 12 US AQI (2.2 µg/m³).

Every month since 2024

202625 so far257 days measured2,707th of 2,791 in the world
Jan48#1,313Feb22#2,729Mar48#1,980Apr24#2,629May19#2,743Jun19 daysJul17#2,752Aug12#2,891Sep16#2,926Oct24#2,357
2025too few days for a mean (a year needs 256)189 days measured
JannoneFebnoneMarnoneAprnoneMay11 daysJun22#2,410Jul21#2,785Aug22#2,816Sep14#3,078Oct26#2,219Nov20 daysDec35#2,376
2024too few days for a mean (a year needs 257)1 day measured
JanFeb1 dayMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Ans'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 Ans 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

18 months
MonthWhy
Jun 202619 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks.
Nov 202520 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
May 202511 of 31 days measured; a month needs 22. The others: 20 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. 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.
Oct 2024No day measured. The others: 31 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 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jun 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 20241 of 29 days measured; a month needs 21. The others: 28 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.

Ans's worst months

MonthUS AQIDays measuredWorld rankEpisode
January 2026 488.7 µg/m³27 of 311,313thof 2,617Europe, January and February 2026
March 2026 488.6 µg/m³28 of 311,980thof 2,971Europe, 18 to 25 March 2026
Europe, 1 to 12 March 2026
December 2025 356.3 µg/m³29 of 312,376thof 3,006–
October 2025 264.6 µg/m³23 of 312,219thof 2,614–
April 2026 244.4 µg/m³30 of 302,629thof 2,941–
February 2026 224.0 µg/m³26 of 282,729thof 2,866Europe, January and February 2026

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.

Ans's worst days

DayUS AQIEpisode
26 Jan 2026 10336.3 µg/m³Europe, January and February 2026
8 Mar 2026 8728.5 µg/m³Europe, 1 to 12 March 2026
7 Mar 2026 8527.4 µg/m³Europe, 1 to 12 March 2026
25 Jan 2026 8426.6 µg/m³Europe, January and February 2026
23 Mar 2026 8326.5 µg/m³Europe, 18 to 25 March 2026
29 Dec 2025 7321.0 µg/m³–
24 Mar 2026 7220.3 µg/m³Europe, 18 to 25 March 2026
11 Oct 2025 7119.9 µg/m³–
29 Jan 2026 7119.9 µg/m³Europe, January and February 2026
11 Jan 2026 7019.2 µg/m³–

Daily means, the highest since 1 Feb 2024; 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, Ans, Belgium, 1 Feb 2024 – 10 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/be/ans/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.

Ans 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).