SmogRank / World / United States / Maine / March 2023

Most polluted cities in Maine, United States, March 2023

3 cities in Maine, United States ranked by their average PM2.5 over the 31 days. Worst: Bangor at 4.7 µg/m³, #783 of 867 cities in the world. Cleanest: Portland at 3.5. A city needs measurements on 70% of the days to be ranked.

OpenAQ's archive, where our readings come from, has almost none for 20 of these 31 days. Cities in the United States and Europe have them from the EPA's and the European Environment Agency's own records of the same monitors; many cities elsewhere are missing from this board, not clean. Why.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

← Bangor 0% 0.75%0
Every city in Maine, United States ranked for March 2023, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Bangor
    0%
  2. 2Lewiston
    0%
  3. 3Portland
    0%
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

All cities in the world, March 2023 · All cities in United States, March 2023 · Maine now

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SmogRank, most polluted cities in Maine, United States, PM2.5, March 2023, smogrank.com/us/region/maine/history/2023-03 (accessed 6 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.