EnviroNearby

Clinton County, Ohio air quality history

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

83%
Good days in 2025
41
Median daily AQI, 2025
3
Days above 100 in 2025
243
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Clinton, Ohio on 243 days. 202 of those days (83%) 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 ozone on 243 days. Across the years with fuller monitoring, the share of Good days rose: an average of 69% in 1980–1982 versus 80% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (243 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.

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 108 of 167 days1980: Moderate 23 of 167 days1980: Unhealthy for Sensitive Groups 18 of 167 days1980: Unhealthy 14 of 167 days1980: Very Unhealthy 4 of 167 days19801981: Good 226 of 322 days1981: Moderate 53 of 322 days1981: Unhealthy for Sensitive Groups 27 of 322 days1981: Unhealthy 14 of 322 days1981: Very Unhealthy 2 of 322 days1982: Good 217 of 301 days1982: Moderate 42 of 301 days1982: Unhealthy for Sensitive Groups 32 of 301 days1982: Unhealthy 10 of 301 days1983: Good 122 of 233 days1983: Moderate 45 of 233 days1983: Unhealthy for Sensitive Groups 34 of 233 days1983: Unhealthy 28 of 233 days1983: Very Unhealthy 4 of 233 days1986: Good 112 of 182 days1986: Moderate 40 of 182 days1986: Unhealthy for Sensitive Groups 23 of 182 days1986: Unhealthy 7 of 182 days1987: Good 107 of 211 days1987: Moderate 59 of 211 days1987: Unhealthy for Sensitive Groups 29 of 211 days1987: Unhealthy 16 of 211 days19871988: Good 113 of 207 days1988: Moderate 55 of 207 days1988: Unhealthy for Sensitive Groups 20 of 207 days1988: Unhealthy 16 of 207 days1988: Very Unhealthy 3 of 207 days1989: Good 124 of 204 days1989: Moderate 51 of 204 days1989: Unhealthy for Sensitive Groups 24 of 204 days1989: Unhealthy 4 of 204 days1989: Very Unhealthy 1 of 204 days1990: Good 120 of 197 days1990: Moderate 46 of 197 days1990: Unhealthy for Sensitive Groups 20 of 197 days1990: Unhealthy 11 of 197 days1991: Good 95 of 211 days1991: Moderate 67 of 211 days1991: Unhealthy for Sensitive Groups 34 of 211 days1991: Unhealthy 13 of 211 days1991: Very Unhealthy 2 of 211 days1992: Good 125 of 209 days1992: Moderate 69 of 209 days1992: Unhealthy for Sensitive Groups 14 of 209 days1992: Unhealthy 1 of 209 days19921993: Good 102 of 205 days1993: Moderate 71 of 205 days1993: Unhealthy for Sensitive Groups 25 of 205 days1993: Unhealthy 7 of 205 days1994: Good 116 of 212 days1994: Moderate 55 of 212 days1994: Unhealthy for Sensitive Groups 26 of 212 days1994: Unhealthy 15 of 212 days1995: Good 97 of 205 days1995: Moderate 62 of 205 days1995: Unhealthy for Sensitive Groups 33 of 205 days1995: Unhealthy 12 of 205 days1995: Very Unhealthy 1 of 205 days1996: Good 122 of 214 days1996: Moderate 53 of 214 days1996: Unhealthy for Sensitive Groups 27 of 214 days1996: Unhealthy 11 of 214 days1996: Very Unhealthy 1 of 214 days1997: Good 119 of 209 days1997: Moderate 58 of 209 days1997: Unhealthy for Sensitive Groups 26 of 209 days1997: Unhealthy 6 of 209 days19971998: Good 91 of 209 days1998: Moderate 66 of 209 days1998: Unhealthy for Sensitive Groups 39 of 209 days1998: Unhealthy 12 of 209 days1998: Very Unhealthy 1 of 209 days1999: Good 86 of 214 days1999: Moderate 69 of 214 days1999: Unhealthy for Sensitive Groups 39 of 214 days1999: Unhealthy 20 of 214 days2000: Good 112 of 214 days2000: Moderate 80 of 214 days2000: Unhealthy for Sensitive Groups 14 of 214 days2000: Unhealthy 7 of 214 days2000: Very Unhealthy 1 of 214 days2001: Good 116 of 214 days2001: Moderate 63 of 214 days2001: Unhealthy for Sensitive Groups 28 of 214 days2001: Unhealthy 5 of 214 days2001: Very Unhealthy 2 of 214 days2002: Good 103 of 207 days2002: Moderate 56 of 207 days2002: Unhealthy for Sensitive Groups 32 of 207 days2002: Unhealthy 15 of 207 days2002: Very Unhealthy 1 of 207 days20022003: Good 122 of 213 days2003: Moderate 65 of 213 days2003: Unhealthy for Sensitive Groups 20 of 213 days2003: Unhealthy 6 of 213 days2004: Good 145 of 214 days2004: Moderate 54 of 214 days2004: Unhealthy for Sensitive Groups 14 of 214 days2004: Unhealthy 1 of 214 days2005: Good 113 of 214 days2005: Moderate 65 of 214 days2005: Unhealthy for Sensitive Groups 33 of 214 days2005: Unhealthy 3 of 214 days2006: Good 121 of 214 days2006: Moderate 75 of 214 days2006: Unhealthy for Sensitive Groups 17 of 214 days2006: Unhealthy 1 of 214 days2007: Good 105 of 214 days2007: Moderate 67 of 214 days2007: Unhealthy for Sensitive Groups 40 of 214 days2007: Unhealthy 2 of 214 days20072008: Good 137 of 209 days2008: Moderate 62 of 209 days2008: Unhealthy for Sensitive Groups 9 of 209 days2008: Unhealthy 1 of 209 days2009: Good 155 of 210 days2009: Moderate 52 of 210 days2009: Unhealthy for Sensitive Groups 3 of 210 days2010: Good 115 of 213 days2010: Moderate 89 of 213 days2010: Unhealthy for Sensitive Groups 9 of 213 days2011: Good 131 of 214 days2011: Moderate 61 of 214 days2011: Unhealthy for Sensitive Groups 19 of 214 days2011: Unhealthy 3 of 214 days2012: Good 123 of 214 days2012: Moderate 77 of 214 days2012: Unhealthy for Sensitive Groups 10 of 214 days2012: Unhealthy 4 of 214 days20122013: Good 184 of 213 days2013: Moderate 28 of 213 days2013: Unhealthy for Sensitive Groups 1 of 213 days2014: Good 163 of 212 days2014: Moderate 47 of 212 days2014: Unhealthy for Sensitive Groups 2 of 212 days2015: Good 182 of 214 days2015: Moderate 29 of 214 days2015: Unhealthy for Sensitive Groups 3 of 214 days2016: Good 154 of 211 days2016: Moderate 53 of 211 days2016: Unhealthy for Sensitive Groups 4 of 211 days2017: Good 206 of 245 days2017: Moderate 36 of 245 days2017: Unhealthy for Sensitive Groups 3 of 245 days20172018: Good 202 of 245 days2018: Moderate 42 of 245 days2018: Unhealthy for Sensitive Groups 1 of 245 days2019: Good 203 of 244 days2019: Moderate 41 of 244 days2020: Good 205 of 229 days2020: Moderate 24 of 229 days2021: Good 209 of 240 days2021: Moderate 31 of 240 days2022: Good 216 of 245 days2022: Moderate 28 of 245 days2022: Unhealthy for Sensitive Groups 1 of 245 days20222023: Good 199 of 242 days2023: Moderate 39 of 242 days2023: Unhealthy for Sensitive Groups 4 of 242 days2024: Good 176 of 240 days2024: Moderate 60 of 240 days2024: Unhealthy for Sensitive Groups 4 of 240 days2025: Good 202 of 243 days2025: Moderate 38 of 243 days2025: Unhealthy for Sensitive Groups 3 of 243 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 1511981: 90th percentile AQI 1191982: 90th percentile AQI 1151983: 90th percentile AQI 1641986: 90th percentile AQI 1151987: 90th percentile AQI 1361988: 90th percentile AQI 1471989: 90th percentile AQI 1151990: 90th percentile AQI 1191991: 90th percentile AQI 1431992: 90th percentile AQI 901993: 90th percentile AQI 1221994: 90th percentile AQI 1331995: 90th percentile AQI 1331996: 90th percentile AQI 1261997: 90th percentile AQI 1121998: 90th percentile AQI 1431999: 90th percentile AQI 1502000: 90th percentile AQI 1052001: 90th percentile AQI 1192002: 90th percentile AQI 1432003: 90th percentile AQI 1082004: 90th percentile AQI 932005: 90th percentile AQI 1192006: 90th percentile AQI 1002007: 90th percentile AQI 1152008: 90th percentile AQI 842009: 90th percentile AQI 772010: 90th percentile AQI 872011: 90th percentile AQI 1012012: 90th percentile AQI 972013: 90th percentile AQI 542014: 90th percentile AQI 642015: 90th percentile AQI 612016: 90th percentile AQI 742017: 90th percentile AQI 612018: 90th percentile AQI 642019: 90th percentile AQI 582020: 90th percentile AQI 542021: 90th percentile AQI 542022: 90th percentile AQI 542023: 90th percentile AQI 672024: 90th percentile AQI 672025: 90th percentile AQI 611980: Median AQI 321981: Median AQI 371982: Median AQI 361983: Median AQI 481986: Median AQI 451987: Median AQI 501988: Median AQI 471989: Median AQI 481990: Median AQI 441991: Median AQI 611992: Median AQI 441993: Median AQI 511994: Median AQI 491995: Median AQI 511996: Median AQI 491997: Median AQI 471998: Median AQI 641999: Median AQI 642000: Median AQI 502001: Median AQI 492002: Median AQI 512003: Median AQI 482004: Median AQI 452005: Median AQI 492006: Median AQI 482007: Median AQI 512008: Median AQI 472009: Median AQI 442010: Median AQI 492011: Median AQI 472012: Median AQI 492013: Median AQI 412014: Median AQI 442015: Median AQI 412016: Median AQI 442017: Median AQI 422018: Median AQI 412019: Median AQI 432020: Median AQI 392021: Median AQI 392022: Median AQI 402023: Median AQI 442024: Median AQI 442025: Median AQI 411980198719921997200220072012201720222025
  • 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
Ozone243100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20252432023830004161112Ozone
20242401766040004467112Ozone
20232421993940004467129Ozone
20222452162810004054140Ozone
2021240209310000395484Ozone
2020229205240000395497Ozone
20192442034100004358100Ozone
20182452024210004164112Ozone
20172452063630004261143Ozone
20162111545340004474112Ozone
20152141822930004161119Ozone
20142121634720004464122Ozone
20132131842810004154122Ozone
201221412377104004997187Ozone
2011214131611930047101161Ozone
20102131158990004987133Ozone
20092101555230004477108Ozone
20082091376291004784154Ozone
2007214105674020051115164Ozone
2006214121751710048100161Ozone
2005214113653330049119179Ozone
200421414554141004593154Ozone
2003213122652060048108195Ozone
20022071035632151051143207Ozone
2001214116632852049119203Ozone
2000214112801471050105205Ozone
1999214866939200064150195Ozone
1998209916639121064143201Ozone
1997209119582660047112197Ozone
19962141225327111049126205Ozone
1995205976233121051133205Ozone
19942121165526150049133200Ozone
1993205102712570051122190Ozone
199220912569141004490154Ozone
1991211956734132061143203Ozone
19901971204620110044119192Ozone
1989204124512441048115205Ozone
19882071135520163047147206Ozone
19872111075929160050136197Ozone
1986182112402370045115192Ozone
19832331224534284048164233Ozone
19823012174232100036115195Ozone
19813222265327142037119205Ozone
19801671082318144032151214Ozone

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