SmogRank / Countries / United States / Maine

Most polluted cities in Maine, United States

4 measured cities, last 24 hours; 0 above the WHO 24-hour guideline. Worst: Augusta at 5.0 µg/m³, #1,025 in the world.

4 good

  1. 1Augusta 5.00.3×
  2. 2Portland 4.60.3×
  3. 3Bangor 3.60.2×
  4. 4Lewiston 3.30.2×
Good0–9.0
Moderate9.1–35.4
Sensitive groups35.5–55.4
Unhealthy55.5–125.4
Very unhealthy125.5–225.4
Hazardous225.5+

Estimated: cities without a monitor

Maine cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City7-day estimateBand
West Scarborough≈ 3 µg/m³Good
South Portland≈ 3 µg/m³Good
South Portland Gardens≈ 3 µg/m³Good
Auburn≈ 3 µg/m³Good
Biddeford≈ 3 µg/m³Good
Sanford≈ 2 µg/m³Good
Saco≈ 3 µg/m³Good
Westbrook≈ 3 µg/m³Good
Waterville≈ 2 µg/m³Good
Brunswick≈ 2 µg/m³Good

Updated 2026-10-01 23:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.