SmogRank / United States / Pennsylvania / York
York, month by month
York, Pennsylvania has a measured daily mean on 1,322 days since 1 January 2023. Its worst month was June 2023, at 90 US AQI (29.8 µg/m³), 92nd of 1,603 cities on that month's world ranking. Its cleanest was May 2025, at 27 US AQI (4.9 µg/m³). 2025 averaged 49 US AQI (8.9 µg/m³), against 42 US AQI (7.5 µg/m³) in 2024.
Every month since 2023
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
1 month
| Month | Why |
|---|---|
| Oct 2023 | 21 of 31 days measured; a month needs 22. The others: 10 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.
York's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| June 2023 | 9029.8 µg/m³ | 92ndof 1,603 | Eastern United States and Canada, June and July 2023 Eastern United States and Canada, May and June 2023 |
| July 2026 | 7622.4 µg/m³ | 269thof 2,784 | Northern United States and Canada, July 2026 North-eastern United States, June and July 2026 |
| February 2026 | 6818.1 µg/m³ | 640thof 2,866 | North-eastern United States and Canada, 14 to 19 February 2026 Pennsylvania, United States, February 2026and 1 more |
| December 2025 | 6315.7 µg/m³ | 696thof 3,006 | Pennsylvania and New York, United States, December 2025 |
| January 2026 | 5712.3 µg/m³ | 911thof 2,617 | North-eastern United States, January 2026 |
| November 2025 | 5611.9 µg/m³ | 774thof 2,715 | Pennsylvania and New Jersey, United States, November 2025 |
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.
York's worst days
| Day | US AQI | Episode |
|---|---|---|
| 8 Jun 2023 | 268193.0 µg/m³ | Eastern United States and Canada, May and June 2023 |
| 17 Jul 2026 | 260185.0 µg/m³ | Northern United States and Canada, July 2026 |
| 7 Jun 2023 | 194117.0 µg/m³ | Eastern United States and Canada, May and June 2023 |
| 29 Jun 2023 | 17792.8 µg/m³ | Eastern United States and Canada, June and July 2023 |
| 16 Jul 2026 | 16981.3 µg/m³ | Northern United States and Canada, July 2026 |
| 18 Jul 2026 | 16575.4 µg/m³ | Northern United States and Canada, July 2026 |
| 30 Jun 2023 | 15866.0 µg/m³ | Eastern United States and Canada, June and July 2023 |
| 6 Jun 2023 | 12143.6 µg/m³ | Eastern United States and Canada, May and June 2023 |
| 21 Nov 2025 | 11641.7 µg/m³ | Pennsylvania and New Jersey, United States, November 2025 |
| 6 Dec 2025 | 11039.3 µg/m³ | – |
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, York, Pennsylvania, United States, 1 Jan 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/york/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.
York 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).