SmogRank / United States / Illinois / Wheaton
Wheaton, month by month
Wheaton has a measured daily mean on 262 days since 25 September 2025. Its worst month was July 2026, at 96 US AQI (33.1 µg/m³), 103rd of 2,784 cities on that month's world ranking. Its cleanest was January 2026, at 47 US AQI (8.5 µg/m³).
Every month since 2025
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
5 months
| Month | Why |
|---|---|
| Jun 2026 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| May 2026 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Apr 2026 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Mar 2026 | 12 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks. |
| Sep 2025 | 6 of 30 days measured; a month needs 21. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Wheaton's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| July 2026 | 9633.1 µg/m³ | 103rdof 2,784 | – |
| August 2026 | 6617.2 µg/m³ | 319thof 2,896 | – |
| February 2026 | 6516.4 µg/m³ | 717thof 2,866 | North-eastern United States and Canada, 14 to 19 February 2026 North-eastern United States and Canada, 9 to 10 February 2026 |
| December 2025 | 6416.0 µg/m³ | 685thof 3,006 | Northern United States, December 2025 |
| November 2025 | 5511.1 µg/m³ | 864thof 2,715 | – |
| September 2026 | 529.9 µg/m³ | 669thof 2,981 | – |
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.
Wheaton's worst days
| Day | US AQI | Episode |
|---|---|---|
| 16 Jul 2026 | 262187.0 µg/m³ | – |
| 17 Jul 2026 | 205129.5 µg/m³ | – |
| 19 Jul 2026 | 15662.1 µg/m³ | – |
| 20 Jul 2026 | 14453.1 µg/m³ | – |
| 4 Mar 2026 | 11842.3 µg/m³ | – |
| 6 Jan 2026 | 11139.6 µg/m³ | North-eastern United States and Canada around Milwaukee, 6 January 2026 |
| 5 Mar 2026 | 11139.4 µg/m³ | – |
| 15 Feb 2026 | 10436.7 µg/m³ | North-eastern United States and Canada, 14 to 19 February 2026 |
| 14 Aug 2026 | 9734.0 µg/m³ | – |
| 18 Jul 2026 | 9733.7 µg/m³ | – |
Daily means, the highest since 25 Sept 2025; 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, Wheaton, United States, 25 Sep 2025 – 11 Oct 2026. Monitor data from AirGradient via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/us/wheaton/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.
Wheaton now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 17:07 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).