EnviroNearby

Greene County, Ohio air quality history

Daily Air Quality Index summaries from EPA monitors in Greene, Ohio, 1989–2025.

85%
Good days in 2025
40
Median daily AQI, 2025
2
Days above 100 in 2025
245
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Greene, Ohio on 245 days. 209 of those days (85%) were in the Good range, and the median daily AQI was 40. That median is lower than 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 245 days. Across the years with fuller monitoring, the share of Good days rose: an average of 70% in 1989–1998 versus 82% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (245 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.

Years with fewer than 120 monitored days (1991, 1992, 1993, 1994, 1995, 1996…) 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%1989: Good 229 of 233 days1989: Moderate 4 of 233 days19891990: Good 108 of 111 days1990: Moderate 3 of 111 days1991: Good 58 of 60 days1991: Moderate 2 of 60 days1992: Good 59 of 60 days1992: Moderate 1 of 60 days1993: Good 56 of 60 days1993: Moderate 4 of 60 days1994: Good 59 of 61 days1994: Moderate 2 of 61 days19941995: Good 58 of 59 days1995: Moderate 1 of 59 days1996: Good 5 of 5 days1997: Good 142 of 239 days1997: Moderate 65 of 239 days1997: Unhealthy for Sensitive Groups 23 of 239 days1997: Unhealthy 9 of 239 days1998: Good 126 of 238 days1998: Moderate 74 of 238 days1998: Unhealthy for Sensitive Groups 26 of 238 days1998: Unhealthy 11 of 238 days1998: Very Unhealthy 1 of 238 days1999: Good 136 of 236 days1999: Moderate 63 of 236 days1999: Unhealthy for Sensitive Groups 27 of 236 days1999: Unhealthy 10 of 236 days19992000: Good 169 of 233 days2000: Moderate 54 of 233 days2000: Unhealthy for Sensitive Groups 8 of 233 days2000: Unhealthy 1 of 233 days2000: Very Unhealthy 1 of 233 days2001: Good 147 of 237 days2001: Moderate 74 of 237 days2001: Unhealthy for Sensitive Groups 14 of 237 days2001: Unhealthy 2 of 237 days2002: Good 139 of 239 days2002: Moderate 64 of 239 days2002: Unhealthy for Sensitive Groups 24 of 239 days2002: Unhealthy 12 of 239 days2003: Good 167 of 248 days2003: Moderate 65 of 248 days2003: Unhealthy for Sensitive Groups 12 of 248 days2003: Unhealthy 4 of 248 days2004: Good 149 of 257 days2004: Moderate 95 of 257 days2004: Unhealthy for Sensitive Groups 13 of 257 days20042005: Good 109 of 264 days2005: Moderate 126 of 264 days2005: Unhealthy for Sensitive Groups 27 of 264 days2005: Unhealthy 2 of 264 days2006: Good 133 of 265 days2006: Moderate 119 of 265 days2006: Unhealthy for Sensitive Groups 13 of 265 days2007: Good 122 of 262 days2007: Moderate 123 of 262 days2007: Unhealthy for Sensitive Groups 16 of 262 days2007: Unhealthy 1 of 262 days2008: Good 136 of 264 days2008: Moderate 120 of 264 days2008: Unhealthy for Sensitive Groups 8 of 264 days2009: Good 157 of 264 days2009: Moderate 102 of 264 days2009: Unhealthy for Sensitive Groups 5 of 264 days20092010: Good 135 of 365 days2010: Moderate 226 of 365 days2010: Unhealthy for Sensitive Groups 4 of 365 days2011: Good 166 of 354 days2011: Moderate 176 of 354 days2011: Unhealthy for Sensitive Groups 12 of 354 days2012: Good 139 of 363 days2012: Moderate 212 of 363 days2012: Unhealthy for Sensitive Groups 11 of 363 days2012: Unhealthy 1 of 363 days2013: Good 170 of 365 days2013: Moderate 192 of 365 days2013: Unhealthy for Sensitive Groups 2 of 365 days2013: Unhealthy 1 of 365 days2014: Good 153 of 362 days2014: Moderate 207 of 362 days2014: Unhealthy for Sensitive Groups 2 of 362 days20142015: Good 213 of 365 days2015: Moderate 148 of 365 days2015: Unhealthy for Sensitive Groups 4 of 365 days2016: Good 229 of 366 days2016: Moderate 136 of 366 days2016: Unhealthy for Sensitive Groups 1 of 366 days2017: Good 238 of 364 days2017: Moderate 125 of 364 days2017: Unhealthy for Sensitive Groups 1 of 364 days2018: Good 210 of 363 days2018: Moderate 152 of 363 days2018: Unhealthy for Sensitive Groups 1 of 363 days2019: Good 213 of 243 days2019: Moderate 30 of 243 days20192020: Good 220 of 245 days2020: Moderate 25 of 245 days2021: Good 221 of 244 days2021: Moderate 23 of 244 days2022: Good 209 of 242 days2022: Moderate 32 of 242 days2022: Unhealthy for Sensitive Groups 1 of 242 days2023: Good 187 of 244 days2023: Moderate 53 of 244 days2023: Unhealthy for Sensitive Groups 4 of 244 days2024: Good 198 of 234 days2024: Moderate 35 of 234 days2024: Unhealthy for Sensitive Groups 1 of 234 days20242025: Good 209 of 245 days2025: Moderate 34 of 245 days2025: Unhealthy for Sensitive Groups 2 of 245 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 year0501001501989: 90th percentile AQI 271990: 90th percentile AQI 261991: 90th percentile AQI 381992: 90th percentile AQI 331993: 90th percentile AQI 461994: 90th percentile AQI 361995: 90th percentile AQI 361996: 90th percentile AQI 301997: 90th percentile AQI 1151998: 90th percentile AQI 1221999: 90th percentile AQI 1222000: 90th percentile AQI 772001: 90th percentile AQI 972002: 90th percentile AQI 1222003: 90th percentile AQI 842004: 90th percentile AQI 862005: 90th percentile AQI 1012006: 90th percentile AQI 872007: 90th percentile AQI 902008: 90th percentile AQI 802009: 90th percentile AQI 722010: 90th percentile AQI 802011: 90th percentile AQI 772012: 90th percentile AQI 802013: 90th percentile AQI 672014: 90th percentile AQI 682015: 90th percentile AQI 652016: 90th percentile AQI 672017: 90th percentile AQI 612018: 90th percentile AQI 642019: 90th percentile AQI 542020: 90th percentile AQI 512021: 90th percentile AQI 502022: 90th percentile AQI 512023: 90th percentile AQI 672024: 90th percentile AQI 612025: 90th percentile AQI 581989: Median AQI 131990: Median AQI 151991: Median AQI 211992: Median AQI 211993: Median AQI 171994: Median AQI 191995: Median AQI 181996: Median AQI 191997: Median AQI 451998: Median AQI 491999: Median AQI 472000: Median AQI 432001: Median AQI 462002: Median AQI 462003: Median AQI 442004: Median AQI 472005: Median AQI 572006: Median AQI 502007: Median AQI 522008: Median AQI 502009: Median AQI 472010: Median AQI 552011: Median AQI 522012: Median AQI 542013: Median AQI 512014: Median AQI 532015: Median AQI 462016: Median AQI 442017: Median AQI 442018: Median AQI 472019: Median AQI 412020: Median AQI 392021: Median AQI 392022: Median AQI 402023: Median AQI 442024: Median AQI 432025: Median AQI 40198919941999200420092014201920242025
  • 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
Ozone245100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20252452093420004058105Ozone
20242341983510004361119Ozone
20232441875340004467126Ozone
20222422093210004051119Ozone
2021244221230000395097Ozone
2020245220250000395193Ozone
2019243213300000415490Ozone
201836321015210004764122PM2.5
201736423812510004461101PM2.5
201636622913610004467105PM2.5
201536521314840004665105PM2.5
201436215320720005368113PM2.5
201336517019221005167162PM2.5
2012363139212111005480164PM2.5
2011354166176120005277136PM2.5
201036513522640005580115PM2.5
200926415710250004772119Ozone
200826413612080005080143Ozone
2007262122123161005290166Ozone
2006265133119130005087150Ozone
20052641091262720057101161Ozone
200425714995130004786147Ozone
200324816765124004484187Ozone
20022391396424120046122190Ozone
200123714774142004697161Ozone
20002331695481104377201Ozone
19992361366327100047122177Ozone
19982381267426111049122201Ozone
1997239142652390045115195Ozone
19965500000193030PM10
1995595810000183652PM10
1994615920000193654PM10
1993605640000174653PM10
1992605910000213351PM10
1991605820000213851PM10
199011110830000152659PM10
198923322940000132759CO

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 1989–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem