SmogRank / Belgium / Flanders / Melsele

Melsele, month by month

Melsele has a measured daily mean on 1,128 days since 14 February 2023. Its worst month was February 2025, at 74 US AQI (21.2 µg/m³), 475th of 2,633 cities on that month's world ranking. Its cleanest was April 2024, at 28 US AQI (5.0 µg/m³). 2025 averaged 53 US AQI (10.0 µg/m³), against 52 US AQI (9.6 µg/m³) in 2024.

Every month since 2023

202651 so far264 days measured1,301st of 2,791 in the world
202452 for the year270 days measured625th of 2,097 in the world
202352 for the year270 days measured537th of 1,355 in the world
Each square is a month's mean PM2.5 in US AQI from Melsele's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Melsele marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

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
MonthWhy
Jun 202619 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks.
Oct 202415 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Sep 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Aug 202415 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Mar 202415 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Mar 202311 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive.
Feb 20232 of 28 days measured; a month needs 20. The others: 13 missing from OpenAQ's archive.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Melsele's worst months

MonthUS AQIDays measuredWorld rankEpisode
February 2025 7421.2 µg/m³25 of 28475thof 2,633Europe, 14 February to 1 March 2025
Europe, 1 to 14 February 2025
March 2025 6516.5 µg/m³24 of 31820thof 2,862Europe, March 2025
Germany, Poland and 25 more countries, March 2025and 1 more
March 2026 6114.6 µg/m³31 of 31885thof 2,971Europe, 18 to 25 March 2026
Europe, 1 to 12 March 2026
January 2025 6013.8 µg/m³29 of 31566thof 2,474Germany, France and 19 more countries, January 2025
Europe, January 2025and 1 more
January 2026 5913.5 µg/m³26 of 31834thof 2,617Europe, January and February 2026
May 2023 5712.3 µg/m³28 of 31245thof 1,600–

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.

Melsele's worst days

DayUS AQIEpisode
10 Feb 2025 13047.4 µg/m³Europe, 1 to 14 February 2025
26 Jan 2026 12645.8 µg/m³Europe, January and February 2026
9 Sept 2023 12143.8 µg/m³United Kingdom, Belgium and 2 more countries, September 2023
25 Mar 2025 12143.7 µg/m³Europe, March 2025
15 Feb 2023 12143.6 µg/m³Europe, 6 to 25 February 2023
8 Mar 2026 11842.4 µg/m³Europe, 1 to 12 March 2026
10 Mar 2025 11541.3 µg/m³Germany, Poland and 25 more countries, March 2025
14 Feb 2025 10838.5 µg/m³Europe, 14 February to 1 March 2025
Europe, 1 to 14 February 2025
20 Jan 2025 10838.4 µg/m³Germany, France and 19 more countries, January 2025
7 Mar 2026 10336.2 µg/m³Europe, 1 to 12 March 2026

Daily means, the highest since 14 Feb 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, Melsele, Belgium, 14 Feb 2023 – 11 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/be/melsele/history (accessed 12 Oct 2026).

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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.

Melsele 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).