EnviroNearby

Garrett County, Maryland air quality history

Daily Air Quality Index summaries from EPA monitors in Garrett, Maryland, 1992–2025.

87%
Good days in 2025
39
Median daily AQI, 2025
0
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 Garrett, Maryland on 365 days. 318 of those days (87%) were in the Good range, and the median daily AQI was 39. That median is about the same as the typical monitored county in Maryland (median 39.5 across 16 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 249 days. Across the years with fuller monitoring, the share of Good days rose: an average of 68% in 2004–2006 versus 85% in 2023–2025.

Years with fewer than 120 monitored days (1993, 1994, 1995, 1996, 1997, 1998…) are shown in the table but left out of comparisons and trend statements.

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%1992: Good 56 of 56 days19921993: Good 60 of 60 days1994: Good 56 of 59 days1994: Moderate 3 of 59 days1995: Good 57 of 60 days1995: Moderate 3 of 60 days1996: Good 58 of 61 days1996: Moderate 3 of 61 days1997: Good 61 of 61 days19971998: Good 55 of 55 days2004: Good 163 of 245 days2004: Moderate 75 of 245 days2004: Unhealthy for Sensitive Groups 7 of 245 days2005: Good 235 of 357 days2005: Moderate 103 of 357 days2005: Unhealthy for Sensitive Groups 18 of 357 days2005: Unhealthy 1 of 357 days2006: Good 256 of 362 days2006: Moderate 98 of 362 days2006: Unhealthy for Sensitive Groups 8 of 362 days2007: Good 258 of 362 days2007: Moderate 93 of 362 days2007: Unhealthy for Sensitive Groups 11 of 362 days20072008: Good 282 of 364 days2008: Moderate 78 of 364 days2008: Unhealthy for Sensitive Groups 4 of 364 days2009: Good 295 of 365 days2009: Moderate 69 of 365 days2009: Unhealthy for Sensitive Groups 1 of 365 days2010: Good 199 of 365 days2010: Moderate 152 of 365 days2010: Unhealthy for Sensitive Groups 14 of 365 days2011: Good 164 of 363 days2011: Moderate 195 of 363 days2011: Unhealthy for Sensitive Groups 4 of 363 days2012: Good 213 of 359 days2012: Moderate 133 of 359 days2012: Unhealthy for Sensitive Groups 12 of 359 days2012: Unhealthy 1 of 359 days20122013: Good 243 of 365 days2013: Moderate 121 of 365 days2013: Unhealthy for Sensitive Groups 1 of 365 days2014: Good 264 of 365 days2014: Moderate 101 of 365 days2015: Good 261 of 365 days2015: Moderate 104 of 365 days2016: Good 301 of 364 days2016: Moderate 63 of 364 days2017: Good 285 of 364 days2017: Moderate 79 of 364 days20172018: Good 298 of 362 days2018: Moderate 64 of 362 days2019: Good 311 of 365 days2019: Moderate 54 of 365 days2020: Good 345 of 365 days2020: Moderate 20 of 365 days2021: Good 312 of 365 days2021: Moderate 53 of 365 days2022: Good 330 of 365 days2022: Moderate 35 of 365 days20222023: Good 297 of 360 days2023: Moderate 61 of 360 days2023: Unhealthy 2 of 360 days2024: Good 311 of 366 days2024: Moderate 55 of 366 days2025: Good 318 of 365 days2025: Moderate 47 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 year0501001992: 90th percentile AQI 401993: 90th percentile AQI 411994: 90th percentile AQI 481995: 90th percentile AQI 441996: 90th percentile AQI 341997: 90th percentile AQI 351998: 90th percentile AQI 362004: 90th percentile AQI 722005: 90th percentile AQI 842006: 90th percentile AQI 772007: 90th percentile AQI 772008: 90th percentile AQI 642009: 90th percentile AQI 602010: 90th percentile AQI 802011: 90th percentile AQI 722012: 90th percentile AQI 772013: 90th percentile AQI 612014: 90th percentile AQI 582015: 90th percentile AQI 582016: 90th percentile AQI 562017: 90th percentile AQI 562018: 90th percentile AQI 562019: 90th percentile AQI 532020: 90th percentile AQI 472021: 90th percentile AQI 542022: 90th percentile AQI 502023: 90th percentile AQI 582024: 90th percentile AQI 542025: 90th percentile AQI 541992: Median AQI 241993: Median AQI 221994: Median AQI 241995: Median AQI 191996: Median AQI 221997: Median AQI 201998: Median AQI 182004: Median AQI 442005: Median AQI 442006: Median AQI 402007: Median AQI 422008: Median AQI 412009: Median AQI 402010: Median AQI 482011: Median AQI 522012: Median AQI 472013: Median AQI 452014: Median AQI 442015: Median AQI 432016: Median AQI 422017: Median AQI 432018: Median AQI 392019: Median AQI 392020: Median AQI 372021: Median AQI 392022: Median AQI 382023: Median AQI 402024: Median AQI 392025: Median AQI 391992199720072012201720222025
  • 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
Ozone24968%
Fine particles (PM2.5)11130%
Nitrogen dioxide (NO₂)51%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025365318470000395480Ozone
2024366311550000395487Ozone
20233602976102004058170Ozone
2022365330350000385097Ozone
2021365312530000395492Ozone
2020365345200000374771Ozone
2019365311540000395371Ozone
2018362298640000395697Ozone
2017364285790000435687Ozone
2016364301630000425697Ozone
201536526110400004358100Ozone
20143652641010000445887Ozone
201336524312110004561122Ozone
2012359213133121004777154Ozone
201136316419540005272119PM2.5
2010365199152140004880150Ozone
20093652956910004060101Ozone
20083642827840004164115Ozone
200736225893110004277129Ozone
20063622569880004077129Ozone
2005357235103181004484159Ozone
20042451637570004472126Ozone
1998555500000183650PM10
1997616100000203549PM10
1996615830000223475PM10
1995605730000194461PM10
1994595630000244853PM10
1993606000000224148PM10
1992565600000244046PM10

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 Maryland with a similar median AQI in 2025

All monitored counties in Maryland

Source: U.S. EPA AirData, “Annual AQI by County” files for 1992–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem