SmogRank / United States / North Carolina / Winston-Salem
Winston-Salem, month by month
Winston-Salem has a measured daily mean on 1,367 days since 1 January 2023. Its worst month was June 2023, at 70 US AQI (19.1 µg/m³), 283rd of 1,603 cities on that month's world ranking. Its cleanest was October 2025, at 27 US AQI (4.9 µg/m³). 2025 averaged 42 US AQI (7.5 µg/m³), against 44 US AQI (8.0 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
Winston-Salem's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| June 2023 | 7019.1 µg/m³ | 283rdof 1,603 | Eastern United States and Canada, June and July 2023 United States and Canada, June 2023and 1 more |
| July 2023 | 6114.3 µg/m³ | 183rdof 1,432 | United States and Canada, July 2023 Eastern United States and Canada, June and July 2023 |
| July 2026 | 5511.4 µg/m³ | 1,021stof 2,784 | Northern United States and Canada, July 2026 |
| November 2023 | 5410.8 µg/m³ | 462ndof 2,243 | – |
| August 2023 | 5410.7 µg/m³ | 487thof 1,980 | – |
| March 2026 | 5310.3 µg/m³ | 1,593rdof 2,971 | – |
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.
Winston-Salem's worst days
| Day | US AQI | Episode |
|---|---|---|
| 29 Jun 2023 | 15560.5 µg/m³ | Eastern United States and Canada, June and July 2023 |
| 17 Jul 2023 | 14252.1 µg/m³ | United States and Canada, July 2023 |
| 18 Jul 2023 | 13448.8 µg/m³ | United States and Canada, July 2023 |
| 30 Jun 2023 | 11641.5 µg/m³ | Eastern United States and Canada, June and July 2023 |
| 6 Jun 2023 | 11340.3 µg/m³ | Eastern United States and Canada, May and June 2023 |
| 15 Mar 2024 | 11240.1 µg/m³ | Eastern United States, March 2024 |
| 28 Jun 2023 | 9633.0 µg/m³ | Eastern United States and Canada, June and July 2023 |
| 9 Jun 2023 | 9532.6 µg/m³ | Eastern United States and Canada, May and June 2023 |
| 2 Dec 2023 | 9130.6 µg/m³ | – |
| 7 Jun 2023 | 9030.3 µg/m³ | Eastern United States and Canada, May and June 2023 |
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, Winston-Salem, 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/winston-salem/history (accessed 13 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.
Winston-Salem now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-13 01:07 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).