EnviroNearby

Clermont County, Ohio air quality history

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

77%
Good days in 2025
41
Median daily AQI, 2025
3
Days above 100 in 2025
364
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Clermont, Ohio on 364 days. 280 of those days (77%) were in the Good range, and the median daily AQI was 41. That median is about the same as the typical monitored county in Ohio (median 43 across 36 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 189 days. Across the years with fuller monitoring, the share of Good days held roughly steady: an average of 78% in 1980–1982 versus 80% 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 270 of 353 days1980: Moderate 47 of 353 days1980: Unhealthy for Sensitive Groups 23 of 353 days1980: Unhealthy 12 of 353 days1980: Very Unhealthy 1 of 353 days19801981: Good 302 of 363 days1981: Moderate 47 of 363 days1981: Unhealthy for Sensitive Groups 12 of 363 days1981: Unhealthy 2 of 363 days1982: Good 268 of 360 days1982: Moderate 56 of 360 days1982: Unhealthy for Sensitive Groups 31 of 360 days1982: Unhealthy 5 of 360 days1983: Good 249 of 310 days1983: Moderate 34 of 310 days1983: Unhealthy for Sensitive Groups 16 of 310 days1983: Unhealthy 8 of 310 days1983: Very Unhealthy 3 of 310 days1984: Good 255 of 322 days1984: Moderate 45 of 322 days1984: Unhealthy for Sensitive Groups 15 of 322 days1984: Unhealthy 7 of 322 days1985: Good 259 of 346 days1985: Moderate 58 of 346 days1985: Unhealthy for Sensitive Groups 22 of 346 days1985: Unhealthy 6 of 346 days1985: Very Unhealthy 1 of 346 days19851986: Good 212 of 276 days1986: Moderate 34 of 276 days1986: Unhealthy for Sensitive Groups 18 of 276 days1986: Unhealthy 11 of 276 days1986: Very Unhealthy 1 of 276 days1987: Good 106 of 214 days1987: Moderate 58 of 214 days1987: Unhealthy for Sensitive Groups 36 of 214 days1987: Unhealthy 11 of 214 days1987: Very Unhealthy 3 of 214 days1988: Good 63 of 123 days1988: Moderate 21 of 123 days1988: Unhealthy for Sensitive Groups 13 of 123 days1988: Unhealthy 16 of 123 days1988: Very Unhealthy 10 of 123 days1989: Good 118 of 209 days1989: Moderate 57 of 209 days1989: Unhealthy for Sensitive Groups 28 of 209 days1989: Unhealthy 6 of 209 days1990: Good 116 of 199 days1990: Moderate 59 of 199 days1990: Unhealthy for Sensitive Groups 20 of 199 days1990: Unhealthy 4 of 199 days19901991: Good 133 of 199 days1991: Moderate 44 of 199 days1991: Unhealthy for Sensitive Groups 16 of 199 days1991: Unhealthy 6 of 199 days1992: Good 195 of 237 days1992: Moderate 37 of 237 days1992: Unhealthy for Sensitive Groups 5 of 237 days1993: Good 116 of 201 days1993: Moderate 64 of 201 days1993: Unhealthy for Sensitive Groups 21 of 201 days1994: Good 123 of 210 days1994: Moderate 56 of 210 days1994: Unhealthy for Sensitive Groups 22 of 210 days1994: Unhealthy 9 of 210 days1995: Good 113 of 204 days1995: Moderate 54 of 204 days1995: Unhealthy for Sensitive Groups 19 of 204 days1995: Unhealthy 17 of 204 days1995: Very Unhealthy 1 of 204 days19951996: Good 111 of 183 days1996: Moderate 47 of 183 days1996: Unhealthy for Sensitive Groups 21 of 183 days1996: Unhealthy 4 of 183 days1997: Good 129 of 214 days1997: Moderate 60 of 214 days1997: Unhealthy for Sensitive Groups 19 of 214 days1997: Unhealthy 6 of 214 days1998: Good 101 of 213 days1998: Moderate 70 of 213 days1998: Unhealthy for Sensitive Groups 28 of 213 days1998: Unhealthy 14 of 213 days1999: Good 87 of 207 days1999: Moderate 64 of 207 days1999: Unhealthy for Sensitive Groups 40 of 207 days1999: Unhealthy 14 of 207 days1999: Very Unhealthy 2 of 207 days2000: Good 122 of 206 days2000: Moderate 62 of 206 days2000: Unhealthy for Sensitive Groups 15 of 206 days2000: Unhealthy 7 of 206 days20002001: Good 125 of 208 days2001: Moderate 62 of 208 days2001: Unhealthy for Sensitive Groups 19 of 208 days2001: Unhealthy 2 of 208 days2002: Good 113 of 211 days2002: Moderate 58 of 211 days2002: Unhealthy for Sensitive Groups 28 of 211 days2002: Unhealthy 11 of 211 days2002: Very Unhealthy 1 of 211 days2003: Good 123 of 211 days2003: Moderate 71 of 211 days2003: Unhealthy for Sensitive Groups 12 of 211 days2003: Unhealthy 5 of 211 days2004: Good 162 of 213 days2004: Moderate 45 of 213 days2004: Unhealthy for Sensitive Groups 6 of 213 days2005: Good 103 of 258 days2005: Moderate 119 of 258 days2005: Unhealthy for Sensitive Groups 34 of 258 days2005: Unhealthy 2 of 258 days20052006: Good 129 of 260 days2006: Moderate 118 of 260 days2006: Unhealthy for Sensitive Groups 12 of 260 days2006: Unhealthy 1 of 260 days2007: Good 108 of 255 days2007: Moderate 116 of 255 days2007: Unhealthy for Sensitive Groups 27 of 255 days2007: Unhealthy 4 of 255 days2008: Good 134 of 256 days2008: Moderate 118 of 256 days2008: Unhealthy for Sensitive Groups 4 of 256 days2009: Good 150 of 264 days2009: Moderate 112 of 264 days2009: Unhealthy for Sensitive Groups 2 of 264 days2010: Good 87 of 365 days2010: Moderate 263 of 365 days2010: Unhealthy for Sensitive Groups 14 of 365 days2010: Unhealthy 1 of 365 days20102011: Good 122 of 365 days2011: Moderate 226 of 365 days2011: Unhealthy for Sensitive Groups 15 of 365 days2011: Unhealthy 2 of 365 days2012: Good 127 of 366 days2012: Moderate 216 of 366 days2012: Unhealthy for Sensitive Groups 17 of 366 days2012: Unhealthy 5 of 366 days2012: Very Unhealthy 1 of 366 days2013: Good 144 of 344 days2013: Moderate 199 of 344 days2013: Unhealthy for Sensitive Groups 1 of 344 days2014: Good 121 of 353 days2014: Moderate 232 of 353 days2015: Good 163 of 357 days2015: Moderate 191 of 357 days2015: Unhealthy for Sensitive Groups 3 of 357 days20152016: Good 164 of 366 days2016: Moderate 197 of 366 days2016: Unhealthy for Sensitive Groups 5 of 366 days2017: Good 207 of 365 days2017: Moderate 156 of 365 days2017: Unhealthy for Sensitive Groups 2 of 365 days2018: Good 245 of 356 days2018: Moderate 109 of 356 days2018: Unhealthy for Sensitive Groups 2 of 356 days2019: Good 247 of 358 days2019: Moderate 107 of 358 days2019: Unhealthy for Sensitive Groups 4 of 358 days2020: Good 296 of 361 days2020: Moderate 65 of 361 days20202021: Good 263 of 364 days2021: Moderate 101 of 364 days2022: Good 238 of 360 days2022: Moderate 121 of 360 days2022: Unhealthy for Sensitive Groups 1 of 360 days2023: Good 279 of 358 days2023: Moderate 74 of 358 days2023: Unhealthy for Sensitive Groups 4 of 358 days2023: Unhealthy 1 of 358 days2024: Good 305 of 360 days2024: Moderate 52 of 360 days2024: Unhealthy for Sensitive Groups 3 of 360 days2025: Good 280 of 364 days2025: Moderate 81 of 364 days2025: Unhealthy for Sensitive Groups 3 of 364 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 year0501001502001980: 90th percentile AQI 1011981: 90th percentile AQI 741982: 90th percentile AQI 1011983: 90th percentile AQI 931984: 90th percentile AQI 871985: 90th percentile AQI 931986: 90th percentile AQI 1081987: 90th percentile AQI 1361988: 90th percentile AQI 1901989: 90th percentile AQI 1151990: 90th percentile AQI 1081991: 90th percentile AQI 1011992: 90th percentile AQI 641993: 90th percentile AQI 1011994: 90th percentile AQI 1121995: 90th percentile AQI 1331996: 90th percentile AQI 1081997: 90th percentile AQI 1011998: 90th percentile AQI 1261999: 90th percentile AQI 1472000: 90th percentile AQI 1012001: 90th percentile AQI 1012002: 90th percentile AQI 1292003: 90th percentile AQI 972004: 90th percentile AQI 712005: 90th percentile AQI 1082006: 90th percentile AQI 872007: 90th percentile AQI 1082008: 90th percentile AQI 772009: 90th percentile AQI 692010: 90th percentile AQI 832011: 90th percentile AQI 832012: 90th percentile AQI 902013: 90th percentile AQI 692014: 90th percentile AQI 722015: 90th percentile AQI 712016: 90th percentile AQI 692017: 90th percentile AQI 642018: 90th percentile AQI 642019: 90th percentile AQI 612020: 90th percentile AQI 542021: 90th percentile AQI 582022: 90th percentile AQI 592023: 90th percentile AQI 642024: 90th percentile AQI 542025: 90th percentile AQI 581980: Median AQI 281981: Median AQI 311982: Median AQI 341983: Median AQI 311984: Median AQI 311985: Median AQI 351986: Median AQI 331987: Median AQI 541988: Median AQI 491989: Median AQI 491990: Median AQI 461991: Median AQI 441992: Median AQI 361993: Median AQI 481994: Median AQI 461995: Median AQI 491996: Median AQI 471997: Median AQI 451998: Median AQI 541999: Median AQI 642000: Median AQI 482001: Median AQI 472002: Median AQI 492003: Median AQI 472004: Median AQI 422005: Median AQI 572006: Median AQI 512007: Median AQI 542008: Median AQI 502009: Median AQI 482010: Median AQI 582011: Median AQI 562012: Median AQI 542013: Median AQI 532014: Median AQI 552015: Median AQI 522016: Median AQI 522017: Median AQI 482018: Median AQI 442019: Median AQI 442020: Median AQI 392021: Median AQI 422022: Median AQI 442023: Median AQI 412024: Median AQI 392025: Median AQI 411980198519901995200020052010201520202025
  • 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)18952%
Ozone17548%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253642808130004158119PM2.5
20243603055230003954119Ozone
20233582797441004164175Ozone
202236023812110004459129PM2.5
20213642631010000425897PM2.5
20203612966500003954100PM2.5
201935824710740004461140PM2.5
201835624510920004464101PM2.5
201736520715620004864129PM2.5
201636616419750005269133PM2.5
201535716319130005271136PM2.5
201435312123200005572100PM2.5
201334414419910005369126PM2.5
2012366127216175105490202PM2.5
2011365122226152005683179PM2.5
201036587263141005883154PM2.5
200926415011220004869101Ozone
200825613411840005077105Ozone
20072551081162740054108169Ozone
2006260129118121005187154Ozone
20052581031193420057108159Ozone
20042131624560004271140Ozone
200321112371125004797200Ozone
20022111135828111049129208Ozone
2001208125621920047101164Ozone
2000206122621570048101187Ozone
1999207876440142064147213Ozone
19982131017028140054126192Ozone
1997214129601960045101187Ozone
1996183111472140047108177Ozone
19952041135419171049133215Ozone
1994210123562290046112177Ozone
1993201116642100048101150Ozone
19922371953750003664115Ozone
1991199133441660044101172Ozone
1990199116592040046108169Ozone
1989209118572860049115177Ozone
19881236321131610049190258Ozone
19872141065836113054136209Ozone
19862762123418111033108213Ozone
198534625958226103593221Ozone
198432225545157003187174Ozone
198331024934168303193238Ozone
1982360268563150034101192Ozone
198136330247122003174174Ozone
19803532704723121028101205Ozone

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