Baltimore Air Quality in 2019

In 2019, Baltimore's air quality (Baltimore-Columbia-Towson, MD area) had a median daily AQI of 51 (Moderate) across 365 monitored days. 13 days (3.6%) reached Unhealthy for Sensitive Groups or worse, 182 were Good, and the year's peak AQI was 150 (Unhealthy for Sensitive Groups). Ground-level ozone set the daily AQI on 195 of those days. The cleanest month of 2019 was October (median AQI 39, 0 days above 100) and the worst was July (median 67, 5 days above 100, peak 129).

51
Median AQI
Moderate
13
Days above AQI 100
3.6% of 365 days
80
90th percentile AQI
worst 1 day in 10
150
Peak AQI
Unhealthy for Sensitive Groups
O3
Main pollutant
195 of 365 days
182
Good days
49.9% of days
  • Good: 49.9%
  • Moderate: 46.6%
  • Unhealthy for Sensitive Groups: 3.6%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How was Baltimore's air quality in 2019?

Moderate on a typical day: median AQI 51, with 13 days above AQI 100 out of 365 monitored — the 5th cleanest of 7 years on record for the area.

  • Peak AQI in 2019: 150 (Unhealthy for Sensitive Groups).
  • Ground-level ozone was the main pollutant on 195 days.
  • Cleanest month: October; worst: July.

Frequently asked questions

What was the average AQI in Baltimore in 2019?

EPA's Air Quality System puts Baltimore's (Baltimore-Columbia-Towson, MD) median daily AQI for 2019 at 51, which is Moderate. 13 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 150.

Which month had the worst air quality in Baltimore in 2019?

The cleanest month of 2019 was October (median AQI 39, 0 days above 100) and the worst was July (median 67, 5 days above 100, peak 129).

Was 2019 a good or bad year for Baltimore's air?

Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 5th cleanest by days above AQI 100. 2019's median of 51 is in line with the area's typical annual median of 49.

Baltimore month by month in 2019

Baltimore air quality month by month, 2019 (Baltimore-Columbia-Towson, MD, EPA AQS daily AQI)

MonthDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
January3141073PM2.5
February2843098PM2.5
March3152080O3
April3046067O3
May3153077O3
June30513150O3
Julyworst31675129O3
August31613122O3
September30521122O3
Octobercleanest3139061O3
November3052072PM2.5
December31461123PM2.5

How 2019 compares

Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 5th cleanest by days above AQI 100.

2019's median of 51 is in line with the area's typical annual median of 49.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in Baltimore

The latest EPA AirNow observation puts Baltimore's AQI at 31 (PM2.5). The figures above are multi-year annual 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.