Baltimore Air Quality in Fall
Across 2019–2025, Baltimore's fall (September–November) air quality had a median AQI of 46 (Good) over 637 monitored days in the Baltimore-Columbia-Towson, MD area. 0.5% of fall days (3 of 637) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 66.1% of days. The cleanest fall on record here was 2022 (median AQI 44, 0 days above 100) and the worst was 2019 (median 47, 1 day above 100, peak AQI 122).
- Good: 61.4%
- Moderate: 38.1%
- Unhealthy for Sensitive Groups: 0.5%
- Unhealthy or worse: 0.0%
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How is the air in Baltimore in fall?
Good on a typical day: median AQI 46 across 2019–2025, with 0.5% of fall days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓61.4% of fall days were Good (AQI 0–50), 38.1% Moderate (51–100).
- ✓3 days of 637 reached AQI 101+; the fall peak was 122.
- ✓Cleanest month: October; worst month: September.
Frequently asked questions
What is the air quality like in Baltimore in fall?▾
Across 2019–2025, the median daily AQI in Baltimore in fall was 46 (Good). 61.4% of days were Good, 38.1% Moderate, and 0.5% reached Unhealthy for Sensitive Groups or worse, based on 637 monitored days in EPA's Air Quality System.
Is fall a good time for outdoor exercise in Baltimore?▾
A typical fall day in Baltimore sits in the Good range (median AQI 46), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of fall days reached AQI 101+ in 2019–2025.
Which pollutant causes Baltimore's fall air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 66.1% of fall days in Baltimore. The highest fall AQI recorded in 2019–2025 was 122 (Unhealthy for Sensitive Groups), in 2019.
Baltimore fall air quality, year by year
Baltimore fall air quality by year (Baltimore-Columbia-Towson, MD, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019worst | 91 | 47 | 1 | 122 | PM2.5 |
| 2020 | 91 | 45 | 0 | 85 | PM2.5 |
| 2021 | 91 | 51 | 0 | 84 | PM2.5 |
| 2022cleanest | 91 | 44 | 0 | 74 | PM2.5 |
| 2023 | 91 | 43 | 1 | 105 | PM2.5 |
| 2024 | 91 | 44 | 1 | 112 | PM2.5 |
| 2025 | 91 | 46 | 0 | 87 | PM2.5 |
What fall air means in Baltimore
A typical fall day in Baltimore sits in the Good range (median AQI 46), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of fall days reached AQI 101+ in 2019–2025.
Fall's median AQI of 46 is in line with Baltimore's whole-year median of 49, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Fall AQI across every EPA metro area (296,275 metro-days, 2019–2025) is 40, so Baltimore runs above the national Fall norm; 0.5% of its Fall days topped AQI 100 versus 1.5% nationally (about the same).
Within the season, October is the cleanest month (median AQI 44, 0.0% of days above 100) and September the worst (median 45, 1.0% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Baltimore
The latest EPA AirNow observation puts Baltimore's AQI at 43 (PM2.5). The figures above are multi-year season statistics, not today's reading.
View current Baltimore air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Baltimore-Columbia-Towson, MD), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.