Overijse, month by month
Overijse has a measured daily mean on 247 days since 19 September 2025. Its worst month was March 2026, at 64 US AQI (16.0 µg/m³), 761st of 2,971 cities on that month's world ranking. Its cleanest was June 2026, at 21 US AQI (3.8 µg/m³).
Every month since 2025
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
8 months
| Month | Why |
|---|---|
| Oct 2026 | No day measured. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Sep 2026 | 11 of 30 days measured; a month needs 21. The others: 19 with under 18 hours of readings or readings that failed our checks. |
| Aug 2026 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Jan 2026 | 12 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks. |
| Dec 2025 | 11 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks. |
| Nov 2025 | 4 of 30 days measured; a month needs 21. The others: 26 with under 18 hours of readings or readings that failed our checks. |
| Oct 2025 | 7 of 31 days measured; a month needs 22. The others: 24 with under 18 hours of readings or readings that failed our checks. |
| Sep 2025 | 10 of 30 days measured; a month needs 21. The others: 2 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.
Overijse's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| March 2026 | 6416.0 µg/m³ | 761stof 2,971 | Europe, 18 to 25 March 2026 Europe, 1 to 12 March 2026 |
| February 2026 | 437.8 µg/m³ | 2,022ndof 2,866 | – |
| May 2026 | 315.5 µg/m³ | 2,149thof 2,874 | – |
| April 2026 | 295.2 µg/m³ | 2,449thof 2,941 | – |
| July 2026 | 244.4 µg/m³ | 2,667thof 2,784 | – |
| June 2026 | 213.8 µg/m³ | 2,337thof 2,497 | – |
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.
Overijse's worst days
| Day | US AQI | Episode |
|---|---|---|
| 8 Mar 2026 | 14854.5 µg/m³ | Europe, 1 to 12 March 2026 |
| 7 Mar 2026 | 14653.6 µg/m³ | Europe, 1 to 12 March 2026 |
| 26 Jan 2026 | 12645.7 µg/m³ | – |
| 23 Mar 2026 | 12143.7 µg/m³ | Europe, 18 to 25 March 2026 |
| 24 Mar 2026 | 11340.5 µg/m³ | Europe, 18 to 25 March 2026 |
| 20 Mar 2026 | 11239.9 µg/m³ | Europe, 18 to 25 March 2026 |
| 19 Jan 2026 | 10537.1 µg/m³ | – |
| 22 Mar 2026 | 10336.5 µg/m³ | Europe, 18 to 25 March 2026 |
| 9 Mar 2026 | 10236.1 µg/m³ | Europe, 1 to 12 March 2026 |
| 20 Dec 2025 | 9532.6 µg/m³ | – |
Daily means, the highest since 19 Sept 2025; 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, Overijse, Belgium, 19 Sep 2025 – 11 Sep 2026. Monitor data from national networks via OpenAQ and the publishers listed at smogrank.com/sources. smogrank.com/be/overijse/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.
Overijse now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 18:07 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).