Baltimore Air Quality in October
Across 2019–2025, Baltimore's October air quality had a median AQI of 44 (Good) over 217 monitored days in the Baltimore-Columbia-Towson, MD area. 0.0% of October days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 72.4% of days. The cleanest October on record here was 2019 (median AQI 39, 0 days above 100) and the worst was 2021 (median 51, 0 days above 100, peak AQI 59).
- Good: 68.7%
- Moderate: 31.3%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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How is the air in Baltimore in October?
Good on a typical day: median AQI 44 across 2019–2025, with 0.0% of October days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓68.7% of October days were Good (AQI 0–50), 31.3% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the October peak was 84.
- ✓Best October: 2019; worst October: 2021.
Frequently asked questions
What is the air quality like in Baltimore in October?▾
Across 2019–2025, the median daily AQI in Baltimore in October was 44 (Good). 68.7% of days were Good, 31.3% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is October a good time for outdoor exercise in Baltimore?▾
A typical October day in Baltimore sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of October days reached AQI 101+ in 2019–2025.
Which pollutant causes Baltimore's October air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 72.4% of October days in Baltimore. The highest October AQI recorded in 2019–2025 was 84 (Moderate), in 2021.
Baltimore October air quality, year by year
Baltimore October air quality by year (Baltimore-Columbia-Towson, MD, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 31 | 39 | 0 | 61 | O3 |
| 2020 | 31 | 47 | 0 | 55 | PM2.5 |
| 2021worst | 31 | 51 | 0 | 59 | PM2.5 |
| 2022 | 31 | 41 | 0 | 67 | PM2.5 |
| 2023 | 31 | 39 | 0 | 84 | O3 |
| 2024 | 31 | 50 | 0 | 84 | PM2.5 |
| 2025 | 31 | 41 | 0 | 53 | PM2.5 |
What October air means in Baltimore
A typical October day in Baltimore sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of October days reached AQI 101+ in 2019–2025.
October's median AQI of 44 is below Baltimore's whole-year median of 49, making it one of the area's cleaner periods. Nationally, the median October AQI across every EPA metro area (102,872 metro-days, 2019–2025) is 38, so Baltimore runs above the national October norm; 0.0% of its October days topped AQI 100 versus 1.3% nationally (below average).
October is part of Baltimore's fall season (September, October, November); the fall page pools all three months.
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 month 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.