SmogRank / The Netherlands / Utrecht / Utrecht

Utrecht, month by month

Utrecht has a measured daily mean on 1,148 days since 1 January 2023. Its worst month was February 2025, at 68 US AQI (18.3 µg/m³), 677th of 2,633 cities on that month's world ranking. Its cleanest was July 2025, at 18 US AQI (3.3 µg/m³). 2025 averaged 47 US AQI (8.4 µg/m³), against 44 US AQI (8.0 µg/m³) in 2024.

Every month since 2023

2023too few days for a mean (a year needs 256)165 days measured
Jan52#512Feb60#410Mar42#542Apr51#545May18 daysJun18 daysJul7 daysAug5 daysSep4 daysOctnoneNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Utrecht'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 Utrecht 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

8 months
MonthWhy
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 20237 of 31 days measured; a month needs 22. The others: 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 202318 of 31 days measured; a month needs 22. The others: 13 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.

Utrecht's worst months

MonthUS AQIDays measuredWorld rankEpisode
February 2025 6818.3 µg/m³28 of 28677thof 2,633Europe, 14 February to 1 March 2025
Europe, 1 to 14 February 2025
January 2026 6717.5 µg/m³30 of 31599thof 2,617Europe, January and February 2026
Europe, December 2025 to January 2026
March 2026 6214.8 µg/m³31 of 31865thof 2,971Europe, 18 to 25 March 2026
Europe, 1 to 12 March 2026
March 2025 6114.2 µg/m³31 of 311,014thof 2,862Europe, March 2025
Germany, Poland and 25 more countries, March 2025and 1 more
February 2023 6014.0 µg/m³28 of 28410thof 1,129Europe, 6 to 25 February 2023
February 2026 5913.3 µg/m³28 of 28895thof 2,866Europe, January and February 2026

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.

Utrecht's worst days

DayUS AQIEpisode
25 Jan 2026 14955.1 µg/m³Europe, January and February 2026
5 Feb 2026 12143.8 µg/m³Europe, January and February 2026
10 Feb 2025 11440.9 µg/m³Europe, 1 to 14 February 2025
5 Mar 2025 10737.8 µg/m³Germany, Poland and 25 more countries, March 2025
9 Feb 2025 10537.2 µg/m³Europe, 1 to 14 February 2025
10 Mar 2025 10537.2 µg/m³Germany, Poland and 25 more countries, March 2025
4 Mar 2025 10436.6 µg/m³Germany, Poland and 25 more countries, March 2025
9 Mar 2026 10336.5 µg/m³Europe, 1 to 12 March 2026
13 Feb 2025 10135.7 µg/m³Europe, 1 to 14 February 2025
1 Jan 2026 10035.4 µg/m³Europe, December 2025 to January 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, Utrecht, 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/utrecht/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.

Utrecht 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).