Lowell, Massachusetts Air Quality

Lowell air quality today — the AQI, the main pollutant, and whether it’s safe to exercise outside right now

Lowell, MA · Air quality right now

The air quality index in Lowell, MA is 46 (Good) right now — safe for outdoor activity.

Is it safe to be outside in Lowell today?

AQI 46 Yes — air quality is Good

Air is clean — great for outdoor activity.Main pollutant: PM2.5Observed 12:00 AM EDT

Pollutants right now

ExerciseOK to run — no air-quality limits on outdoor exercise.

How to read Lowell’s air quality

Guides: The AQI Scale, Explained · Air Quality Alerts, Decoded · How to Read a Wildfire Smoke Map · Why Wildfire Smoke Travels 1,000 Miles.

Air quality over time in Lowell

Across the EPA’s county records from 2020 to 2025, Lowell’s cleanest year was 2021 (median AQI 37) and its most polluted was 2020 (median AQI 39); the typical (median) day has held roughly steady since 2020.

Lowell’s county air-quality record by year — the median and days in each AQI category, from the EPA’s Annual AQI by County summaries.
YearMedian AQIUnhealthy+Main pollutantUSGModerateGood
2020390PM2.5060306
2021371PM2.5164299
2022380Ozone055310
2023390Ozone183281
2024370Ozone052314
2025380Ozone165299

“USG” is Unhealthy for Sensitive Groups (AQI 101–150); “Unhealthy+” combines the Unhealthy, Very Unhealthy, and Hazardous days. In 2024 the EPA tightened the annual fine-particle (PM2.5) standard to 9 µg/m³ from the previous 12 µg/m³, so counties near the old limit read worse against the new one. Source: EPA AQS annual summaries, 20202025.

Frequently asked

What was the worst year for air quality in Lowell?
In the EPA's 2020–2025 county records, 2021 had the most days above AQI 100: 2 days (1 Unhealthy for Sensitive Groups, 1 Unhealthy or worse). The highest median AQI came in 2020 (39; 2021's was 37).
How many unhealthy air days does Lowell have?
Across 2020–2025, under 1% of the days reported for Lowell's county had an AQI above 100 (4 of 2192), about 1 day a year. 2025 had 1 day.
What's the main air pollutant in Lowell?
Ozone drove Lowell's county AQI on the most days in 4 of 6 years (2020–2025); PM2.5 in 2020, 2021.