SmogRank / Belgium / Wallonia / Hamois
Hamois, month by month
Hamois has a measured daily mean on 1,027 days since 6 May 2023. Its worst month was February 2025, at 55 US AQI (11.2 µg/m³), 1,078th of 2,633 cities on that month's world ranking. Its cleanest was July 2023, at 11 US AQI (2.0 µg/m³).
Every month since 2023
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
7 months
| Month | Why |
|---|---|
| Jun 2026 | 19 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Jan 2026 | 19 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| Sep 2025 | 19 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Oct 2024 | 15 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks. |
| Sep 2024 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Aug 2024 | 15 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks. |
| Mar 2024 | 13 of 31 days measured; a month needs 22. The others: 18 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.
Hamois's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| February 2025 | 5511.2 µg/m³ | 1,078thof 2,633 | Europe, 1 to 14 February 2025 |
| March 2025 | 5310.3 µg/m³ | 1,545thof 2,862 | Europe, March 2025 |
| January 2024 | 498.9 µg/m³ | 1,039thof 2,385 | Europe, 8 to 27 January 2024 |
| March 2026 | 468.3 µg/m³ | 2,060thof 2,971 | Europe, 18 to 25 March 2026 |
| May 2023 | 447.9 µg/m³ | 958thof 1,600 | Europe, May 2023 |
| January 2025 | 386.8 µg/m³ | 1,766thof 2,474 | – |
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.
Hamois's worst days
| Day | US AQI | Episode |
|---|---|---|
| 16 Aug 2026 | 12444.7 µg/m³ | Germany, Belgium and 2 more countries, August 2026 |
| 26 Jan 2026 | 10436.6 µg/m³ | Europe, January and February 2026 |
| 25 Mar 2025 | 9834.3 µg/m³ | Europe, March 2025 |
| 11 Jan 2024 | 9230.9 µg/m³ | Europe, 8 to 27 January 2024 |
| 20 Mar 2026 | 8527.6 µg/m³ | Europe, 18 to 25 March 2026 |
| 27 Feb 2024 | 8527.4 µg/m³ | – |
| 25 Jan 2026 | 8426.7 µg/m³ | Europe, January and February 2026 |
| 18 Jan 2024 | 8225.6 µg/m³ | Europe, 8 to 27 January 2024 |
| 13 Feb 2025 | 8125.4 µg/m³ | Europe, 1 to 14 February 2025 |
| 22 May 2023 | 8125.0 µg/m³ | Europe, May 2023 |
Daily means, the highest since 6 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, Hamois, Belgium, 6 May 2023 – 11 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/be/hamois/history (accessed 12 Oct 2026).
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.
Hamois now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 20:07 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).