EnviroNearby

Cumberland County, Maine air quality history

Daily Air Quality Index summaries from EPA monitors in Cumberland, Maine, 1980–2025.

74%
Good days in 2025
39
Median daily AQI, 2025
5
Days above 100 in 2025
365
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Cumberland, Maine on 365 days. 271 of those days (74%) were in the Good range, and the median daily AQI was 39. That median is higher than the typical monitored county in Maine (median 34 across 11 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 208 days. Across the years with fuller monitoring, the share of Good days rose: an average of 73% in 1980–1982 versus 76% in 2023–2025.

How the days broke down each year

Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.

Share of monitored days in each AQI category, by year0%25%50%75%100%1980: Good 144 of 192 days1980: Moderate 17 of 192 days1980: Unhealthy for Sensitive Groups 16 of 192 days1980: Unhealthy 11 of 192 days1980: Very Unhealthy 4 of 192 days19801981: Good 124 of 167 days1981: Moderate 29 of 167 days1981: Unhealthy for Sensitive Groups 6 of 167 days1981: Unhealthy 5 of 167 days1981: Very Unhealthy 3 of 167 days1982: Good 120 of 173 days1982: Moderate 34 of 173 days1982: Unhealthy for Sensitive Groups 8 of 173 days1982: Unhealthy 8 of 173 days1982: Very Unhealthy 3 of 173 days1983: Good 170 of 239 days1983: Moderate 34 of 239 days1983: Unhealthy for Sensitive Groups 19 of 239 days1983: Unhealthy 11 of 239 days1983: Very Unhealthy 5 of 239 days1984: Good 208 of 292 days1984: Moderate 53 of 292 days1984: Unhealthy for Sensitive Groups 16 of 292 days1984: Unhealthy 11 of 292 days1984: Very Unhealthy 4 of 292 days1985: Good 272 of 361 days1985: Moderate 64 of 361 days1985: Unhealthy for Sensitive Groups 15 of 361 days1985: Unhealthy 5 of 361 days1985: Very Unhealthy 5 of 361 days19851986: Good 299 of 354 days1986: Moderate 41 of 354 days1986: Unhealthy for Sensitive Groups 7 of 354 days1986: Unhealthy 7 of 354 days1987: Good 263 of 329 days1987: Moderate 50 of 329 days1987: Unhealthy for Sensitive Groups 10 of 329 days1987: Unhealthy 2 of 329 days1987: Very Unhealthy 4 of 329 days1988: Good 293 of 365 days1988: Moderate 33 of 365 days1988: Unhealthy for Sensitive Groups 14 of 365 days1988: Unhealthy 15 of 365 days1988: Very Unhealthy 10 of 365 days1989: Good 310 of 359 days1989: Moderate 35 of 359 days1989: Unhealthy for Sensitive Groups 6 of 359 days1989: Unhealthy 7 of 359 days1989: Very Unhealthy 1 of 359 days1990: Good 314 of 364 days1990: Moderate 35 of 364 days1990: Unhealthy for Sensitive Groups 10 of 364 days1990: Unhealthy 4 of 364 days1990: Very Unhealthy 1 of 364 days19901991: Good 308 of 363 days1991: Moderate 31 of 363 days1991: Unhealthy for Sensitive Groups 12 of 363 days1991: Unhealthy 8 of 363 days1991: Very Unhealthy 4 of 363 days1992: Good 283 of 331 days1992: Moderate 29 of 331 days1992: Unhealthy for Sensitive Groups 10 of 331 days1992: Unhealthy 7 of 331 days1992: Very Unhealthy 2 of 331 days1993: Good 254 of 305 days1993: Moderate 35 of 305 days1993: Unhealthy for Sensitive Groups 11 of 305 days1993: Unhealthy 5 of 305 days1994: Good 237 of 291 days1994: Moderate 36 of 291 days1994: Unhealthy for Sensitive Groups 13 of 291 days1994: Unhealthy 4 of 291 days1994: Very Unhealthy 1 of 291 days1995: Good 319 of 365 days1995: Moderate 31 of 365 days1995: Unhealthy for Sensitive Groups 7 of 365 days1995: Unhealthy 7 of 365 days1995: Very Unhealthy 1 of 365 days19951996: Good 310 of 365 days1996: Moderate 46 of 365 days1996: Unhealthy for Sensitive Groups 6 of 365 days1996: Unhealthy 3 of 365 days1997: Good 315 of 361 days1997: Moderate 29 of 361 days1997: Unhealthy for Sensitive Groups 12 of 361 days1997: Unhealthy 3 of 361 days1997: Very Unhealthy 2 of 361 days1998: Good 221 of 269 days1998: Moderate 37 of 269 days1998: Unhealthy for Sensitive Groups 6 of 269 days1998: Unhealthy 3 of 269 days1998: Very Unhealthy 2 of 269 days1999: Good 180 of 212 days1999: Moderate 23 of 212 days1999: Unhealthy for Sensitive Groups 7 of 212 days1999: Unhealthy 2 of 212 days2000: Good 186 of 214 days2000: Moderate 27 of 214 days2000: Unhealthy for Sensitive Groups 1 of 214 days20002001: Good 229 of 288 days2001: Moderate 47 of 288 days2001: Unhealthy for Sensitive Groups 5 of 288 days2001: Unhealthy 7 of 288 days2002: Good 297 of 365 days2002: Moderate 52 of 365 days2002: Unhealthy for Sensitive Groups 11 of 365 days2002: Unhealthy 5 of 365 days2003: Good 318 of 365 days2003: Moderate 39 of 365 days2003: Unhealthy for Sensitive Groups 8 of 365 days2004: Good 327 of 366 days2004: Moderate 36 of 366 days2004: Unhealthy for Sensitive Groups 3 of 366 days2005: Good 310 of 365 days2005: Moderate 47 of 365 days2005: Unhealthy for Sensitive Groups 8 of 365 days20052006: Good 319 of 365 days2006: Moderate 43 of 365 days2006: Unhealthy for Sensitive Groups 3 of 365 days2007: Good 212 of 262 days2007: Moderate 40 of 262 days2007: Unhealthy for Sensitive Groups 9 of 262 days2007: Unhealthy 1 of 262 days2008: Good 314 of 355 days2008: Moderate 39 of 355 days2008: Unhealthy for Sensitive Groups 2 of 355 days2009: Good 335 of 365 days2009: Moderate 28 of 365 days2009: Unhealthy for Sensitive Groups 2 of 365 days2010: Good 277 of 365 days2010: Moderate 82 of 365 days2010: Unhealthy for Sensitive Groups 4 of 365 days2010: Unhealthy 2 of 365 days20102011: Good 257 of 365 days2011: Moderate 105 of 365 days2011: Unhealthy for Sensitive Groups 2 of 365 days2011: Unhealthy 1 of 365 days2012: Good 278 of 366 days2012: Moderate 85 of 366 days2012: Unhealthy for Sensitive Groups 3 of 366 days2013: Good 232 of 365 days2013: Moderate 128 of 365 days2013: Unhealthy for Sensitive Groups 5 of 365 days2014: Good 260 of 365 days2014: Moderate 103 of 365 days2014: Unhealthy for Sensitive Groups 2 of 365 days2015: Good 233 of 365 days2015: Moderate 131 of 365 days2015: Unhealthy for Sensitive Groups 1 of 365 days20152016: Good 288 of 366 days2016: Moderate 78 of 366 days2017: Good 271 of 365 days2017: Moderate 92 of 365 days2017: Unhealthy for Sensitive Groups 2 of 365 days2018: Good 280 of 365 days2018: Moderate 85 of 365 days2019: Good 208 of 365 days2019: Moderate 157 of 365 days2020: Good 263 of 366 days2020: Moderate 103 of 366 days20202021: Good 319 of 365 days2021: Moderate 43 of 365 days2021: Unhealthy for Sensitive Groups 3 of 365 days2022: Good 323 of 362 days2022: Moderate 36 of 362 days2022: Unhealthy for Sensitive Groups 3 of 362 days2023: Good 266 of 365 days2023: Moderate 96 of 365 days2023: Unhealthy for Sensitive Groups 3 of 365 days2024: Good 291 of 366 days2024: Moderate 74 of 366 days2024: Unhealthy for Sensitive Groups 1 of 366 days2025: Good 271 of 365 days2025: Moderate 89 of 365 days2025: Unhealthy for Sensitive Groups 5 of 365 days2025
  • Good
  • Moderate
  • Unhealthy for Sensitive Groups
  • Unhealthy
  • Very Unhealthy
  • Hazardous

Typical and high-end AQI over time

The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.

Median and 90th-percentile daily AQI, by year0501001501980: 90th percentile AQI 1221981: 90th percentile AQI 971982: 90th percentile AQI 1011983: 90th percentile AQI 1221984: 90th percentile AQI 1051985: 90th percentile AQI 801986: 90th percentile AQI 611987: 90th percentile AQI 711988: 90th percentile AQI 1051989: 90th percentile AQI 611990: 90th percentile AQI 581991: 90th percentile AQI 771992: 90th percentile AQI 641993: 90th percentile AQI 671994: 90th percentile AQI 711995: 90th percentile AQI 581996: 90th percentile AQI 641997: 90th percentile AQI 541998: 90th percentile AQI 611999: 90th percentile AQI 612000: 90th percentile AQI 582001: 90th percentile AQI 772002: 90th percentile AQI 652003: 90th percentile AQI 542004: 90th percentile AQI 512005: 90th percentile AQI 562006: 90th percentile AQI 572007: 90th percentile AQI 582008: 90th percentile AQI 552009: 90th percentile AQI 482010: 90th percentile AQI 612011: 90th percentile AQI 632012: 90th percentile AQI 582013: 90th percentile AQI 632014: 90th percentile AQI 602015: 90th percentile AQI 622016: 90th percentile AQI 562017: 90th percentile AQI 572018: 90th percentile AQI 582019: 90th percentile AQI 592020: 90th percentile AQI 582021: 90th percentile AQI 542022: 90th percentile AQI 512023: 90th percentile AQI 642024: 90th percentile AQI 572025: 90th percentile AQI 621980: Median AQI 401981: Median AQI 411982: Median AQI 441983: Median AQI 401984: Median AQI 411985: Median AQI 391986: Median AQI 351987: Median AQI 381988: Median AQI 361989: Median AQI 331990: Median AQI 351991: Median AQI 361992: Median AQI 351993: Median AQI 341994: Median AQI 351995: Median AQI 331996: Median AQI 361997: Median AQI 361998: Median AQI 391999: Median AQI 362000: Median AQI 362001: Median AQI 382002: Median AQI 372003: Median AQI 372004: Median AQI 352005: Median AQI 372006: Median AQI 342007: Median AQI 362008: Median AQI 342009: Median AQI 332010: Median AQI 392011: Median AQI 402012: Median AQI 402013: Median AQI 442014: Median AQI 412015: Median AQI 442016: Median AQI 392017: Median AQI 402018: Median AQI 412019: Median AQI 472020: Median AQI 422021: Median AQI 362022: Median AQI 362023: Median AQI 402024: Median AQI 372025: Median AQI 391980198519901995200020052010201520202025
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2025

On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.

PollutantDays as main pollutantShare of monitored days
Ozone20857%
Fine particles (PM2.5)14740%
Coarse particles (PM10)103%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253652718950003962136Ozone
20243662917410003757119Ozone
20233652669630004064120Ozone
20223623233630003651109Ozone
20213653194330003654129Ozone
20203662631030000425897PM2.5
201936520815700004759100PM2.5
20183652808500004158100Ozone
20173652719220004057150Ozone
2016366288780000395697PM2.5
201536523313110004462108PM2.5
201436526010320004160109PM2.5
201336523212850004463136PM2.5
20123662788530004058126Ozone
201136525710521004063161PM2.5
20103652778242003961177Ozone
20093653352820003348150Ozone
20083553143920003455119Ozone
20072622124091003658185Ozone
20063653194330003457126Ozone
20053653104780003756143Ozone
20043663273630003551126Ozone
20033653183980003754147Ozone
200236529752115003765195Ozone
20012882294757003877200Ozone
20002141862710003658133Ozone
19992121802372003661195Ozone
19982692213763203961212Ozone
199736131529123203654214Ozone
19963653104663003664166Ozone
19953653193177103358212Ozone
199429123736134103571206Ozone
199330525435115003467187Ozone
199233128329107203564207Ozone
199136330831128403677222Ozone
199036431435104103558216Ozone
19893593103567103361221Ozone
198836529333141510036105239Ozone
198732926350102403871220Ozone
19863542994177003561192Ozone
198536127264155503980232CO
19842922085316114041105222Ozone
19832391703419115040122239Ozone
198217312034883044101230Ozone
19811671242965304197212Ozone
19801921441716114040122234Ozone

What this data can and can’t tell you

It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.

It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.

Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.

Counties in Maine with a similar median AQI in 2025

All monitored counties in Maine

Source: U.S. EPA AirData, “Annual AQI by County” files for 1980–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem