SmogRank / Belgium / Flanders / Knokke-Heist
Knokke-Heist, month by month
Knokke-Heist has a measured daily mean on 472 days since 21 May 2025. Its worst month was March 2026, at 63 US AQI (15.3 µg/m³), 821st of 2,971 cities on that month's world ranking. Its cleanest was September 2025, at 30 US AQI (5.4 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
2 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. |
| May 2025 | 11 of 31 days measured; a month needs 22. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Knokke-Heist's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| March 2026 | 6315.3 µg/m³ | 821stof 2,971 | Europe, 18 to 25 March 2026 Europe, 1 to 12 March 2026 |
| January 2026 | 5611.8 µg/m³ | 937thof 2,617 | Europe, January and February 2026 |
| December 2025 | 529.6 µg/m³ | 1,433rdof 3,006 | – |
| May 2026 | 529.4 µg/m³ | 908thof 2,874 | – |
| February 2026 | 488.6 µg/m³ | 1,795thof 2,866 | Europe, January and February 2026 |
| April 2026 | 488.6 µg/m³ | 1,355thof 2,941 | – |
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.
Knokke-Heist's worst days
| Day | US AQI | Episode |
|---|---|---|
| 26 Jan 2026 | 14051.4 µg/m³ | Europe, January and February 2026 |
| 8 Mar 2026 | 12746.2 µg/m³ | Europe, 1 to 12 March 2026 |
| 23 Mar 2026 | 10236.1 µg/m³ | Europe, 18 to 25 March 2026 |
| 9 Mar 2026 | 8828.8 µg/m³ | Europe, 1 to 12 March 2026 |
| 25 Jun 2026 | 8628.1 µg/m³ | Belgium, France and 2 more countries, June 2026 |
| 22 Mar 2026 | 8627.9 µg/m³ | Europe, 18 to 25 March 2026 |
| 24 Mar 2026 | 8527.5 µg/m³ | Europe, 18 to 25 March 2026 |
| 4 Mar 2026 | 8527.3 µg/m³ | Europe, 1 to 12 March 2026 |
| 6 Mar 2026 | 8225.7 µg/m³ | Europe, 1 to 12 March 2026 |
| 7 Mar 2026 | 8225.7 µg/m³ | Europe, 1 to 12 March 2026 |
Daily means, the highest since 21 May 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, Knokke-Heist, Belgium, 21 May 2025 – 11 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/be/knokke-heist/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.
Knokke-Heist now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 19:07 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).