SmogRank / United States / Massachusetts / Framingham
Framingham, month by month
Framingham has a measured daily mean on 643 days since 27 December 2024. Its worst month was June 2025, at 53 US AQI (10.3 µg/m³), 1,216th of 2,508 cities on that month's world ranking. Its cleanest was September 2026, at 20 US AQI (3.6 µg/m³).
Every month since 2024
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 |
|---|---|
| Dec 2024 | 5 of 31 days measured; a month needs 22. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Framingham's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| June 2025 | 5310.3 µg/m³ | 1,216thof 2,508 | Northern United States and Canada, June 2025 Northern United States and Canada, May and June 2025 |
| July 2026 | 519.3 µg/m³ | 1,542ndof 2,784 | Northern United States and Canada, July 2026 |
| July 2025 | 478.4 µg/m³ | 1,676thof 2,889 | North-eastern United States and Canada, 29 July to 9 August 2025 North-eastern United States and Canada, 24 to 28 July 2025 |
| August 2025 | 468.3 µg/m³ | 1,720thof 2,901 | North-eastern United States and Canada, 29 July to 9 August 2025 |
| February 2026 | 448.0 µg/m³ | 1,977thof 2,866 | – |
| January 2026 | 386.9 µg/m³ | 1,846thof 2,617 | – |
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.
Framingham's worst days
| Day | US AQI | Episode |
|---|---|---|
| 18 Jul 2026 | 11340.4 µg/m³ | Northern United States and Canada, July 2026 |
| 8 Jun 2025 | 8728.3 µg/m³ | Northern United States and Canada, May and June 2025 |
| 15 Jul 2026 | 8527.4 µg/m³ | Northern United States and Canada, July 2026 |
| 5 Aug 2025 | 8426.8 µg/m³ | North-eastern United States and Canada, 29 July to 9 August 2025 |
| 9 Jun 2025 | 8326.2 µg/m³ | Northern United States and Canada, May and June 2025 |
| 12 Jun 2025 | 8125.4 µg/m³ | Northern United States and Canada, June 2025 |
| 27 Jul 2025 | 8125.1 µg/m³ | North-eastern United States and Canada, 24 to 28 July 2025 |
| 4 Aug 2025 | 8125.0 µg/m³ | North-eastern United States and Canada, 29 July to 9 August 2025 |
| 18 Feb 2026 | 8024.6 µg/m³ | – |
| 26 Jul 2025 | 7723.1 µg/m³ | North-eastern United States and Canada, 24 to 28 July 2025 |
Daily means, the highest since 27 Dec 2024; 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, Framingham, United States, 27 Dec 2024 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/framingham/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.
Framingham 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).