EnviroNearby

Cuyahoga County, Ohio air quality history

Daily Air Quality Index summaries from EPA monitors in Cuyahoga, Ohio, 1980–2025.

43%
Good days in 2025
53
Median daily AQI, 2025
4
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 Cuyahoga, Ohio on 365 days. 158 of those days (43%) were in the Good range, and the median daily AQI was 53. That median is higher than the typical monitored county in Ohio (median 43 across 36 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 228 days. Across the years with fuller monitoring, the share of Good days fell: an average of 68% in 1980–1982 versus 38% 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 266 of 366 days1980: Moderate 88 of 366 days1980: Unhealthy for Sensitive Groups 9 of 366 days1980: Unhealthy 3 of 366 days19801981: Good 268 of 365 days1981: Moderate 71 of 365 days1981: Unhealthy for Sensitive Groups 15 of 365 days1981: Unhealthy 10 of 365 days1981: Very Unhealthy 1 of 365 days1982: Good 210 of 365 days1982: Moderate 102 of 365 days1982: Unhealthy for Sensitive Groups 42 of 365 days1982: Unhealthy 8 of 365 days1982: Very Unhealthy 3 of 365 days1983: Good 210 of 365 days1983: Moderate 111 of 365 days1983: Unhealthy for Sensitive Groups 30 of 365 days1983: Unhealthy 10 of 365 days1983: Very Unhealthy 4 of 365 days1984: Good 209 of 366 days1984: Moderate 105 of 366 days1984: Unhealthy for Sensitive Groups 47 of 366 days1984: Unhealthy 4 of 366 days1984: Very Unhealthy 1 of 366 days1985: Good 227 of 365 days1985: Moderate 101 of 365 days1985: Unhealthy for Sensitive Groups 31 of 365 days1985: Unhealthy 6 of 365 days19851986: Good 230 of 365 days1986: Moderate 102 of 365 days1986: Unhealthy for Sensitive Groups 27 of 365 days1986: Unhealthy 5 of 365 days1986: Very Unhealthy 1 of 365 days1987: Good 181 of 365 days1987: Moderate 144 of 365 days1987: Unhealthy for Sensitive Groups 26 of 365 days1987: Unhealthy 13 of 365 days1987: Very Unhealthy 1 of 365 days1988: Good 144 of 366 days1988: Moderate 173 of 366 days1988: Unhealthy for Sensitive Groups 24 of 366 days1988: Unhealthy 18 of 366 days1988: Very Unhealthy 7 of 366 days1989: Good 151 of 365 days1989: Moderate 188 of 365 days1989: Unhealthy for Sensitive Groups 21 of 365 days1989: Unhealthy 5 of 365 days1990: Good 177 of 365 days1990: Moderate 164 of 365 days1990: Unhealthy for Sensitive Groups 18 of 365 days1990: Unhealthy 6 of 365 days19901991: Good 178 of 365 days1991: Moderate 142 of 365 days1991: Unhealthy for Sensitive Groups 27 of 365 days1991: Unhealthy 18 of 365 days1992: Good 205 of 366 days1992: Moderate 144 of 366 days1992: Unhealthy for Sensitive Groups 11 of 366 days1992: Unhealthy 6 of 366 days1993: Good 190 of 365 days1993: Moderate 152 of 365 days1993: Unhealthy for Sensitive Groups 15 of 365 days1993: Unhealthy 7 of 365 days1993: Very Unhealthy 1 of 365 days1994: Good 172 of 365 days1994: Moderate 161 of 365 days1994: Unhealthy for Sensitive Groups 27 of 365 days1994: Unhealthy 5 of 365 days1995: Good 201 of 365 days1995: Moderate 127 of 365 days1995: Unhealthy for Sensitive Groups 29 of 365 days1995: Unhealthy 8 of 365 days19951996: Good 211 of 366 days1996: Moderate 128 of 366 days1996: Unhealthy for Sensitive Groups 15 of 366 days1996: Unhealthy 11 of 366 days1996: Very Unhealthy 1 of 366 days1997: Good 205 of 365 days1997: Moderate 138 of 365 days1997: Unhealthy for Sensitive Groups 19 of 365 days1997: Unhealthy 3 of 365 days1998: Good 201 of 365 days1998: Moderate 130 of 365 days1998: Unhealthy for Sensitive Groups 27 of 365 days1998: Unhealthy 6 of 365 days1998: Very Unhealthy 1 of 365 days1999: Good 49 of 365 days1999: Moderate 258 of 365 days1999: Unhealthy for Sensitive Groups 50 of 365 days1999: Unhealthy 8 of 365 days2000: Good 47 of 366 days2000: Moderate 278 of 366 days2000: Unhealthy for Sensitive Groups 35 of 366 days2000: Unhealthy 6 of 366 days20002001: Good 47 of 365 days2001: Moderate 259 of 365 days2001: Unhealthy for Sensitive Groups 50 of 365 days2001: Unhealthy 9 of 365 days2002: Good 61 of 365 days2002: Moderate 268 of 365 days2002: Unhealthy for Sensitive Groups 13 of 365 days2002: Unhealthy 22 of 365 days2002: Very Unhealthy 1 of 365 days2003: Good 49 of 365 days2003: Moderate 285 of 365 days2003: Unhealthy for Sensitive Groups 25 of 365 days2003: Unhealthy 4 of 365 days2003: Very Unhealthy 2 of 365 days2004: Good 61 of 366 days2004: Moderate 277 of 366 days2004: Unhealthy for Sensitive Groups 26 of 366 days2004: Unhealthy 2 of 366 days2005: Good 166 of 365 days2005: Moderate 164 of 365 days2005: Unhealthy for Sensitive Groups 31 of 365 days2005: Unhealthy 4 of 365 days20052006: Good 206 of 365 days2006: Moderate 135 of 365 days2006: Unhealthy for Sensitive Groups 21 of 365 days2006: Unhealthy 3 of 365 days2007: Good 204 of 365 days2007: Moderate 135 of 365 days2007: Unhealthy for Sensitive Groups 22 of 365 days2007: Unhealthy 4 of 365 days2008: Good 215 of 366 days2008: Moderate 132 of 366 days2008: Unhealthy for Sensitive Groups 16 of 366 days2008: Unhealthy 3 of 366 days2009: Good 233 of 365 days2009: Moderate 125 of 365 days2009: Unhealthy for Sensitive Groups 7 of 365 days2010: Good 80 of 365 days2010: Moderate 252 of 365 days2010: Unhealthy for Sensitive Groups 32 of 365 days2010: Unhealthy 1 of 365 days20102011: Good 53 of 365 days2011: Moderate 287 of 365 days2011: Unhealthy for Sensitive Groups 21 of 365 days2011: Unhealthy 4 of 365 days2012: Good 70 of 366 days2012: Moderate 252 of 366 days2012: Unhealthy for Sensitive Groups 35 of 366 days2012: Unhealthy 9 of 366 days2013: Good 104 of 365 days2013: Moderate 256 of 365 days2013: Unhealthy for Sensitive Groups 4 of 365 days2013: Unhealthy 1 of 365 days2014: Good 148 of 365 days2014: Moderate 209 of 365 days2014: Unhealthy for Sensitive Groups 7 of 365 days2014: Unhealthy 1 of 365 days2015: Good 182 of 365 days2015: Moderate 178 of 365 days2015: Unhealthy for Sensitive Groups 5 of 365 days20152016: Good 146 of 366 days2016: Moderate 215 of 366 days2016: Unhealthy for Sensitive Groups 5 of 366 days2017: Good 181 of 365 days2017: Moderate 180 of 365 days2017: Unhealthy for Sensitive Groups 4 of 365 days2018: Good 165 of 365 days2018: Moderate 189 of 365 days2018: Unhealthy for Sensitive Groups 11 of 365 days2019: Good 116 of 365 days2019: Moderate 245 of 365 days2019: Unhealthy for Sensitive Groups 4 of 365 days2020: Good 148 of 366 days2020: Moderate 208 of 366 days2020: Unhealthy for Sensitive Groups 9 of 366 days2020: Unhealthy 1 of 366 days20202021: Good 100 of 365 days2021: Moderate 261 of 365 days2021: Unhealthy for Sensitive Groups 4 of 365 days2022: Good 137 of 365 days2022: Moderate 220 of 365 days2022: Unhealthy for Sensitive Groups 6 of 365 days2022: Unhealthy 2 of 365 days2023: Good 117 of 365 days2023: Moderate 235 of 365 days2023: Unhealthy for Sensitive Groups 9 of 365 days2023: Unhealthy 3 of 365 days2023: Very Unhealthy 1 of 365 days2024: Good 136 of 366 days2024: Moderate 224 of 366 days2024: Unhealthy for Sensitive Groups 6 of 366 days2025: Good 158 of 365 days2025: Moderate 203 of 365 days2025: Unhealthy for Sensitive Groups 4 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 741981: 90th percentile AQI 801982: 90th percentile AQI 1081983: 90th percentile AQI 1081984: 90th percentile AQI 1111985: 90th percentile AQI 1011986: 90th percentile AQI 971987: 90th percentile AQI 1051988: 90th percentile AQI 1291989: 90th percentile AQI 901990: 90th percentile AQI 871991: 90th percentile AQI 1121992: 90th percentile AQI 771993: 90th percentile AQI 871994: 90th percentile AQI 991995: 90th percentile AQI 1011996: 90th percentile AQI 901997: 90th percentile AQI 841998: 90th percentile AQI 971999: 90th percentile AQI 1152000: 90th percentile AQI 1022001: 90th percentile AQI 1102002: 90th percentile AQI 992003: 90th percentile AQI 972004: 90th percentile AQI 962005: 90th percentile AQI 1002006: 90th percentile AQI 882007: 90th percentile AQI 902008: 90th percentile AQI 842009: 90th percentile AQI 752010: 90th percentile AQI 982011: 90th percentile AQI 922012: 90th percentile AQI 1052013: 90th percentile AQI 762014: 90th percentile AQI 772015: 90th percentile AQI 742016: 90th percentile AQI 732017: 90th percentile AQI 722018: 90th percentile AQI 772019: 90th percentile AQI 742020: 90th percentile AQI 702021: 90th percentile AQI 772022: 90th percentile AQI 762023: 90th percentile AQI 832024: 90th percentile AQI 772025: 90th percentile AQI 781980: Median AQI 401981: Median AQI 371982: Median AQI 471983: Median AQI 481984: Median AQI 471985: Median AQI 441986: Median AQI 441987: Median AQI 511988: Median AQI 551989: Median AQI 551990: Median AQI 511991: Median AQI 511992: Median AQI 471993: Median AQI 501994: Median AQI 511995: Median AQI 471996: Median AQI 471997: Median AQI 461998: Median AQI 471999: Median AQI 702000: Median AQI 712001: Median AQI 722002: Median AQI 662003: Median AQI 652004: Median AQI 642005: Median AQI 542006: Median AQI 452007: Median AQI 472008: Median AQI 472009: Median AQI 432010: Median AQI 652011: Median AQI 642012: Median AQI 652013: Median AQI 582014: Median AQI 542015: Median AQI 512016: Median AQI 542017: Median AQI 512018: Median AQI 532019: Median AQI 562020: Median AQI 542021: Median AQI 572022: Median AQI 542023: Median AQI 572024: Median AQI 542025: Median AQI 531980198519901995200020052010201520202025
  • 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
Fine particles (PM2.5)22862%
Ozone11732%
Coarse particles (PM10)164%
Carbon monoxide (CO)31%
Nitrogen dioxide (NO₂)1<1%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536515820340005378150PM2.5
202436613622460005477122PM2.5
202336511723593105783234PM2.5
202236513722062005476158PM2.5
202136510026140005777115PM2.5
202036614820891005470152PM2.5
201936511624540005674108PM2.5
2018365165189110005377133PM2.5
201736518118040005172126PM2.5
201636614621550005473112PM2.5
201536518217850005174112PM2.5
201436514820971005477181PM2.5
201336510425641005876151PM2.5
2012366702523590065105192PM2.5
201136553287214006492157PM2.5
201036580252321006598155PM2.5
200936523312570004375140Ozone
2008366215132163004784161Ozone
2007365204135224004790195Ozone
2006365206135213004588161Ozone
20053651661643140054100182PM2.5
200436661277262006496152PM2.5
200336549285254206597207PM2.5
2002365612681322106699202PM2.5
2001365472595090072110185PM2.5
2000366472783560071102174PM2.5
1999365492585080070115192PM2.5
1998365201130276104797206NO2
1997365205138193004684174NO2
19963662111281511104790209PM10
19953652011272980047101190NO2
1994365172161275005199195NO2
1993365190152157105087230PM10
1992366205144116004777177NO2
199136517814227180051112195NO2
1990365177164186005187185NO2
1989365151188215005590176NO2
198836614417324187055129230NO2
198736518114426131051105215NO2
1986365230102275104497205NO2
19853652271013160044101174NO2
19843662091054741047111201NO2
198336521011130104048108221NO2
19823652101024283047108214NO2
1981365268711510103780209CO
19803662668893004074192CO

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 Ohio with a similar median AQI in 2025

All monitored counties in Ohio

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