Baltimore Air Quality in March

Across 2019–2025, Baltimore's March air quality had a median AQI of 45 (Good) over 216 monitored days in the Baltimore-Columbia-Towson, MD area. 0.0% of March days (0 of 216) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 64.8% of days. The cleanest March on record here was 2024 (median AQI 42, 0 days above 100) and the worst was 2019 (median 52, 0 days above 100, peak AQI 80).

45
Median AQI
Good
0.0%
Days above AQI 100
0 of 216 days
57
90th percentile AQI
worst 1 day in 10
87
Peak AQI
Moderate
O3
Main pollutant
64.8% of days
75.5%
Good days
163 of 216
  • Good: 75.5%
  • Moderate: 24.5%
  • Unhealthy for Sensitive Groups: 0.0%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How is the air in Baltimore in March?

Good on a typical day: median AQI 45 across 2019–2025, with 0.0% of March days above AQI 100. Ground-level ozone is the main driver.

  • 75.5% of March days were Good (AQI 0–50), 24.5% Moderate (51–100).
  • 0 days of 216 reached AQI 101+; the March peak was 87.
  • Best March: 2024; worst March: 2019.

Frequently asked questions

What is the air quality like in Baltimore in March?

Across 2019–2025, the median daily AQI in Baltimore in March was 45 (Good). 75.5% of days were Good, 24.5% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 216 monitored days in EPA's Air Quality System.

Is March a good time for outdoor exercise in Baltimore?

A typical March day in Baltimore sits in the Good range (median AQI 45), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of March days reached AQI 101+ in 2019–2025.

Which pollutant causes Baltimore's March air quality problems?

Ground-level ozone set the daily AQI on 64.8% of March days in Baltimore. The highest March AQI recorded in 2019–2025 was 87 (Moderate), in 2019.

Baltimore March air quality, year by year

Baltimore March air quality by year (Baltimore-Columbia-Towson, MD, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
2019worst3152080O3
20203043059O3
20213146084O3
20223144068O3
20233146067O3
2024cleanest3142087O3
20253145069O3

What March air means in Baltimore

A typical March day in Baltimore sits in the Good range (median AQI 45), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of March days reached AQI 101+ in 2019–2025.

March's median AQI of 45 is below Baltimore's whole-year median of 49, making it one of the area's cleaner periods. Nationally, the median March AQI across every EPA metro area (102,455 metro-days, 2019–2025) is 42, so Baltimore runs in line with the national March norm; 0.0% of its March days topped AQI 100 versus 0.4% nationally (about the same).

March is part of Baltimore's spring season (March, April, May); the spring 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.