SmogRank / Belgium / Flanders / Willebroek
Willebroek, month by month
Willebroek has a measured daily mean on 1,167 days since 11 January 2023. Its worst month was February 2025, at 70 US AQI (19.3 µg/m³), 619th of 2,633 cities on that month's world ranking. Its cleanest was September 2025, at 23 US AQI (4.2 µg/m³). 2025 averaged 52 US AQI (9.4 µg/m³), against 51 US AQI (9.1 µg/m³) in 2024.
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
6 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. |
| 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 | 13 of 31 days measured; a month needs 22. The others: 18 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 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.
Willebroek's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| February 2025 | 7019.3 µg/m³ | 619thof 2,633 | Europe, 14 February to 1 March 2025 Europe, 1 to 14 February 2025 |
| February 2023 | 6717.5 µg/m³ | 214thof 1,129 | Europe, 6 to 25 February 2023 |
| March 2025 | 6315.8 µg/m³ | 875thof 2,862 | Europe, March 2025 Germany, Poland and 25 more countries, March 2025and 1 more |
| March 2026 | 6114.2 µg/m³ | 920thof 2,971 | Europe, 18 to 25 March 2026 Europe, 1 to 12 March 2026 |
| January 2025 | 5913.4 µg/m³ | 586thof 2,474 | Germany, France and 19 more countries, January 2025 Europe, January 2025and 1 more |
| January 2026 | 5812.8 µg/m³ | 886thof 2,617 | Europe, 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.
Willebroek's worst days
| Day | US AQI | Episode |
|---|---|---|
| 26 Jan 2026 | 13047.2 µg/m³ | Europe, January and February 2026 |
| 15 Feb 2023 | 12746.0 µg/m³ | Europe, 6 to 25 February 2023 |
| 10 Feb 2025 | 12746.0 µg/m³ | Europe, 1 to 14 February 2025 |
| 25 Mar 2025 | 12444.7 µg/m³ | Europe, March 2025 |
| 7 Mar 2026 | 12143.7 µg/m³ | Europe, 1 to 12 March 2026 |
| 14 Feb 2025 | 11340.4 µg/m³ | Europe, 14 February to 1 March 2025 Europe, 1 to 14 February 2025 |
| 10 Feb 2023 | 11240.0 µg/m³ | Europe, 6 to 25 February 2023 |
| 10 Mar 2025 | 11139.7 µg/m³ | Germany, Poland and 25 more countries, March 2025 |
| 8 Mar 2026 | 10838.2 µg/m³ | Europe, 1 to 12 March 2026 |
| 15 Jan 2025 | 10336.2 µg/m³ | Germany, France and 19 more countries, January 2025 Europe, January 2025 |
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, Willebroek, Belgium, 11 Jan 2023 – 11 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/be/willebroek/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.
Willebroek now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 21:07 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).