Baltimore Air Quality in January

Across 2019–2025, Baltimore's January air quality had a median AQI of 43 (Good) over 217 monitored days in the Baltimore-Columbia-Towson, MD area. 0.0% of January days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 74.7% of days. The cleanest January on record here was 2020 (median AQI 37, 0 days above 100) and the worst was 2022 (median 53, 0 days above 100, peak AQI 68).

43
Median AQI
Good
0.0%
Days above AQI 100
0 of 217 days
63
90th percentile AQI
worst 1 day in 10
84
Peak AQI
Moderate
PM2.5
Main pollutant
74.7% of days
61.8%
Good days
134 of 217
  • Good: 61.8%
  • Moderate: 38.2%
  • Unhealthy for Sensitive Groups: 0.0%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How is the air in Baltimore in January?

Good on a typical day: median AQI 43 across 2019–2025, with 0.0% of January days above AQI 100. Fine particulate matter (PM2.5) is the main driver.

  • 61.8% of January days were Good (AQI 0–50), 38.2% Moderate (51–100).
  • 0 days of 217 reached AQI 101+; the January peak was 84.
  • Best January: 2020; worst January: 2022.

Frequently asked questions

What is the air quality like in Baltimore in January?

Across 2019–2025, the median daily AQI in Baltimore in January was 43 (Good). 61.8% of days were Good, 38.2% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.

Is January a good time for outdoor exercise in Baltimore?

A typical January day in Baltimore sits in the Good range (median AQI 43), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of January days reached AQI 101+ in 2019–2025.

Which pollutant causes Baltimore's January air quality problems?

Fine particulate matter (PM2.5) set the daily AQI on 74.7% of January days in Baltimore. The highest January AQI recorded in 2019–2025 was 84 (Moderate), in 2022.

Baltimore January air quality, year by year

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

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193141073PM2.5
2020cleanest3137084PM2.5
20213142074PM2.5
2022worst3153068PM2.5
20233141069PM2.5
20243140081PM2.5
20253151075PM2.5

What January air means in Baltimore

A typical January day in Baltimore sits in the Good range (median AQI 43), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of January days reached AQI 101+ in 2019–2025.

January's median AQI of 43 is below Baltimore's whole-year median of 49, making it one of the area's cleaner periods. Nationally, the median January AQI across every EPA metro area (95,602 metro-days, 2019–2025) is 39, so Baltimore runs above the national January norm; 0.0% of its January days topped AQI 100 versus 0.7% nationally (about the same).

January is part of Baltimore's winter season (December, January, February); the winter 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.