SmogRank / Belgium / Flanders / Houthalen
Houthalen, month by month
Houthalen has a measured daily mean on 862 days since 11 January 2023. Its worst month was February 2025, at 76 US AQI (22.7 µg/m³), 393rd of 2,852 cities on that month's world ranking. Its cleanest was September 2025, at 29 US AQI (5.2 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
17 months
| Month | Why |
|---|---|
| Jun 2026 | 16 of 30 days measured; a month needs 21. The others: 6 with no readings from the monitors, 8 with readings for part of the day (a day needs 18 hours). |
| Oct 2024 | 14 of 31 days measured; a month needs 22. The others: 17 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 | 15 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks. |
| Jan 2024 | 2 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks. |
| Dec 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Nov 2023 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Oct 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Sep 2023 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Aug 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jul 2023 | No day measured. The others: 1 missing from OpenAQ's archive, 30 with under 18 hours of readings or readings that failed our checks. |
| Jun 2023 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| May 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Apr 2023 | No day measured. The others: 3 missing from OpenAQ's archive, 27 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 19 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 11 with under 18 hours of readings or readings that failed our checks. |
| Jan 2023 | 7 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.
Houthalen's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| February 2025 | 7622.7 µg/m³ | 393rdof 2,852 | Europe, 14 February to 1 March 2025 Europe, 1 to 14 February 2025 |
| March 2025 | 7120.0 µg/m³ | 620thof 3,102 | Europe, March 2025 Germany, Poland and 25 more countries, March 2025and 1 more |
| February 2023 | 6416.1 µg/m³ | 277thof 1,129 | Europe, 6 to 25 February 2023 |
| January 2026 | 6315.6 µg/m³ | 858thof 2,978 | Europe, January and February 2026 |
| March 2026 | 6315.5 µg/m³ | 913thof 3,285 | Europe, 18 to 25 March 2026 Europe, 1 to 12 March 2026 |
| January 2025 | 5812.7 µg/m³ | 763rdof 2,754 | Germany, France and 19 more countries, January 2025 Europe, January 2025and 1 more |
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.
Houthalen's worst days
| Day | US AQI | Episode |
|---|---|---|
| 25 Mar 2025 | 15257.1 µg/m³ | Europe, March 2025 |
| 10 Feb 2025 | 13951.1 µg/m³ | Europe, 1 to 14 February 2025 |
| 10 Mar 2025 | 13750.1 µg/m³ | Germany, Poland and 25 more countries, March 2025 |
| 26 Jan 2026 | 12746.2 µg/m³ | Europe, January and February 2026 |
| 14 Feb 2025 | 12545.2 µg/m³ | Europe, 14 February to 1 March 2025 Europe, 1 to 14 February 2025 |
| 13 Feb 2025 | 12143.7 µg/m³ | Europe, 1 to 14 February 2025 |
| 7 Mar 2026 | 11541.3 µg/m³ | Europe, 1 to 12 March 2026 |
| 10 Feb 2023 | 10938.9 µg/m³ | Europe, 6 to 25 February 2023 |
| 8 Mar 2026 | 10838.3 µg/m³ | Europe, 1 to 12 March 2026 |
| 25 Jan 2026 | 10838.2 µg/m³ | Europe, January and February 2026 |
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, Houthalen, Belgium, 11 Jan 2023 – 13 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/be/houthalen/history (accessed 13 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.
Houthalen now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-13 22:07 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).