SmogRank / The Netherlands / Utrecht / Lopik

Lopik, month by month

Lopik has a measured daily mean on 1,051 days since 1 January 2023. Its worst month was February 2025, at 71 US AQI (20.1 µg/m³), 564th of 2,633 cities on that month's world ranking. Its cleanest was July 2025, at 20 US AQI (3.6 µg/m³). 2025 averaged 47 US AQI (8.5 µg/m³), against 52 US AQI (9.8 µg/m³) in 2024.

Every month since 2023

202652 so far251 days measured1,147th of 2,793 in the world
2023too few days for a mean (a year needs 256)109 days measured
Jan48#608Feb3 daysMar12 daysApr49#653May18 daysJun14 daysJul6 daysAug5 daysSep4 daysOctnoneNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Lopik'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 Lopik 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

12 months
MonthWhy
Jul 202621 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Nov 202417 of 30 days measured; a month needs 21. 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 202314 of 30 days measured; a month needs 21. The others: 16 with under 18 hours of readings or readings that failed our checks.
May 202318 of 31 days measured; a month needs 22. The others: 13 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.

Lopik's worst months

MonthUS AQIDays measuredWorld rankEpisode
February 2025 7120.1 µg/m³28 of 28564thof 2,633Europe, 14 February to 1 March 2025
Europe, 1 to 14 February 2025
January 2026 6717.7 µg/m³30 of 31587thof 2,617Europe, January and February 2026
March 2025 6114.7 µg/m³31 of 31976thof 2,862Europe, March 2025
Germany, Poland and 25 more countries, March 2025and 1 more
March 2026 6114.7 µg/m³31 of 31877thof 2,971Europe, 18 to 25 March 2026
Europe, 1 to 12 March 2026
February 2026 5913.2 µg/m³27 of 28908thof 2,866Europe, January and February 2026
January 2024 5712.5 µg/m³28 of 31645thof 2,385Europe, 8 to 27 January 2024

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.

Lopik's worst days

DayUS AQIEpisode
25 Jan 2026 14352.5 µg/m³Europe, January and February 2026
10 Feb 2025 12344.4 µg/m³Europe, 1 to 14 February 2025
9 Feb 2025 12143.8 µg/m³Europe, 1 to 14 February 2025
5 Feb 2026 11943.0 µg/m³Europe, January and February 2026
10 Mar 2025 11340.4 µg/m³Germany, Poland and 25 more countries, March 2025
8 Mar 2026 10838.3 µg/m³Europe, 1 to 12 March 2026
26 Jan 2026 10637.4 µg/m³Europe, January and February 2026
13 Feb 2025 9934.9 µg/m³Europe, 1 to 14 February 2025
24 Jan 2026 9934.8 µg/m³Europe, January and February 2026
7 Mar 2026 9834.4 µg/m³Europe, 1 to 12 March 2026

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, Lopik, The Netherlands, 1 Jan 2023 – 11 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/lopik/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.

Lopik 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).