SmogRank / The Netherlands / South Holland / Noordwijkerhout

Noordwijkerhout, month by month

Noordwijkerhout has a measured daily mean on 1,062 days since 1 January 2023. Its worst month was February 2025, at 65 US AQI (16.6 µg/m³), 783rd of 2,633 cities on that month's world ranking. Its cleanest was August 2026, at 26 US AQI (4.7 µg/m³). 2025 averaged 49 US AQI (8.9 µg/m³), against 39 US AQI (7.0 µg/m³) in 2024.

Every month since 2023

2023too few days for a mean (a year needs 256)110 days measured
Jan50#582Feb3 daysMar12 daysApr53#412May16 daysJun18 daysJul6 daysAug5 daysSep4 daysOctnoneNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Noordwijkerhout'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 Noordwijkerhout 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

11 months
MonthWhy
Jul 202618 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Dec 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2023No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Sep 20234 of 30 days measured; a month needs 21. The others: 26 with under 18 hours of readings or readings that failed our checks.
Aug 20235 of 31 days measured; a month needs 22. The others: 26 with under 18 hours of readings or readings that failed our checks.
Jul 20236 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 24 with under 18 hours of readings or readings that failed our checks.
Jun 202318 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks.
May 202316 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Mar 202312 of 31 days measured; a month needs 22. The others: 19 missing from OpenAQ's archive.
Feb 20233 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive.

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

Noordwijkerhout's worst months

MonthUS AQIDays measuredWorld rankEpisode
February 2025 6516.6 µg/m³28 of 28783rdof 2,633Europe, 1 to 14 February 2025
January 2026 6315.3 µg/m³30 of 31743rdof 2,617Europe, January and February 2026
March 2025 6114.5 µg/m³31 of 31991stof 2,862Europe, March 2025
Germany, Poland and 25 more countries, March 2025
February 2026 6014.0 µg/m³28 of 28855thof 2,866Europe, January and February 2026
March 2026 5913.2 µg/m³31 of 311,037thof 2,971Europe, 18 to 25 March 2026
Europe, 1 to 12 March 2026
April 2023 5310.3 µg/m³22 of 30412thof 1,622–

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.

Noordwijkerhout's worst days

DayUS AQIEpisode
25 Jan 2026 14854.4 µg/m³Europe, January and February 2026
20 Jan 2025 12846.5 µg/m³Germany, France and 19 more countries, January 2025
5 Feb 2026 11541.3 µg/m³Europe, January and February 2026
10 Feb 2025 11139.6 µg/m³Europe, 1 to 14 February 2025
10 Mar 2025 10737.9 µg/m³Germany, Poland and 25 more countries, March 2025
4 Mar 2025 10637.7 µg/m³Germany, Poland and 25 more countries, March 2025
5 Mar 2025 10336.2 µg/m³Germany, Poland and 25 more countries, March 2025
15 Feb 2023 10235.9 µg/m³Europe, 6 to 25 February 2023
9 Feb 2025 10235.9 µg/m³Europe, 1 to 14 February 2025
25 Jan 2023 9935.1 µg/m³France, The Netherlands and United Kingdom, January 2023

Daily means, the highest since 1 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, Noordwijkerhout, The Netherlands, 1 Jan 2023 – 12 Oct 2026. Monitor data from RIVM Luchtmeetnet and EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/nl/noordwijkerhout/history (accessed 13 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.

Noordwijkerhout now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-13 02:07 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).