EnviroNearby

Noble County, Ohio air quality history

Daily Air Quality Index summaries from EPA monitors in Noble, Ohio, 1985–2025.

86%
Good days in 2025
37
Median daily AQI, 2025
0
Days above 100 in 2025
362
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Noble, Ohio on 362 days. 311 of those days (86%) were in the Good range, and the median daily AQI was 37. That median is lower than the typical monitored county in Ohio (median 43 across 36 counties), and lower than the typical monitored U.S. county (40). The main pollutant was ozone on 334 days. Across the years with fuller monitoring, the share of Good days rose: an average of 76% in 1993–1995 versus 85% in 2023–2025.

Years with fewer than 120 monitored days (1987, 1988, 1989, 1990, 1991, 1992…) 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%1985: Good 14 of 18 days1985: Moderate 4 of 18 days19851986: Good 43 of 49 days1986: Moderate 6 of 49 days1987: Good 51 of 60 days1987: Moderate 9 of 60 days1988: Good 56 of 60 days1988: Moderate 4 of 60 days1989: Good 46 of 53 days1989: Moderate 7 of 53 days1990: Good 49 of 56 days1990: Moderate 7 of 56 days19901991: Good 53 of 60 days1991: Moderate 6 of 60 days1991: Unhealthy for Sensitive Groups 1 of 60 days1992: Good 52 of 60 days1992: Moderate 8 of 60 days1993: Good 129 of 135 days1993: Moderate 6 of 135 days1994: Good 248 of 353 days1994: Moderate 59 of 353 days1994: Unhealthy for Sensitive Groups 40 of 353 days1994: Unhealthy 6 of 353 days1995: Good 197 of 317 days1995: Moderate 77 of 317 days1995: Unhealthy for Sensitive Groups 28 of 317 days1995: Unhealthy 13 of 317 days1995: Very Unhealthy 2 of 317 days19951996: Good 129 of 152 days1996: Moderate 15 of 152 days1996: Unhealthy for Sensitive Groups 7 of 152 days1996: Unhealthy 1 of 152 days1997: Good 243 of 338 days1997: Moderate 61 of 338 days1997: Unhealthy for Sensitive Groups 30 of 338 days1997: Unhealthy 4 of 338 days1998: Good 212 of 345 days1998: Moderate 77 of 345 days1998: Unhealthy for Sensitive Groups 37 of 345 days1998: Unhealthy 17 of 345 days1998: Very Unhealthy 2 of 345 days1999: Good 241 of 341 days1999: Moderate 65 of 341 days1999: Unhealthy for Sensitive Groups 24 of 341 days1999: Unhealthy 10 of 341 days1999: Very Unhealthy 1 of 341 days2000: Good 252 of 353 days2000: Moderate 80 of 353 days2000: Unhealthy for Sensitive Groups 19 of 353 days2000: Unhealthy 2 of 353 days20002001: Good 233 of 363 days2001: Moderate 98 of 363 days2001: Unhealthy for Sensitive Groups 27 of 363 days2001: Unhealthy 5 of 363 days2002: Good 164 of 254 days2002: Moderate 76 of 254 days2002: Unhealthy for Sensitive Groups 10 of 254 days2002: Unhealthy 4 of 254 days2003: Good 241 of 358 days2003: Moderate 107 of 358 days2003: Unhealthy for Sensitive Groups 7 of 358 days2003: Unhealthy 2 of 358 days2003: Very Unhealthy 1 of 358 days2004: Good 258 of 357 days2004: Moderate 93 of 357 days2004: Unhealthy for Sensitive Groups 6 of 357 days2005: Good 228 of 355 days2005: Moderate 102 of 355 days2005: Unhealthy for Sensitive Groups 24 of 355 days2005: Unhealthy 1 of 355 days20052006: Good 252 of 339 days2006: Moderate 83 of 339 days2006: Unhealthy for Sensitive Groups 4 of 339 days2007: Good 247 of 363 days2007: Moderate 99 of 363 days2007: Unhealthy for Sensitive Groups 17 of 363 days2008: Good 274 of 360 days2008: Moderate 83 of 360 days2008: Unhealthy for Sensitive Groups 3 of 360 days2009: Good 273 of 353 days2009: Moderate 78 of 353 days2009: Unhealthy for Sensitive Groups 2 of 353 days2010: Good 232 of 340 days2010: Moderate 96 of 340 days2010: Unhealthy for Sensitive Groups 12 of 340 days20102011: Good 243 of 304 days2011: Moderate 61 of 304 days2012: Good 238 of 323 days2012: Moderate 80 of 323 days2012: Unhealthy for Sensitive Groups 5 of 323 days2013: Good 285 of 348 days2013: Moderate 62 of 348 days2013: Unhealthy for Sensitive Groups 1 of 348 days2014: Good 285 of 355 days2014: Moderate 69 of 355 days2014: Unhealthy for Sensitive Groups 1 of 355 days2015: Good 296 of 360 days2015: Moderate 63 of 360 days2015: Unhealthy for Sensitive Groups 1 of 360 days20152016: Good 297 of 348 days2016: Moderate 49 of 348 days2016: Unhealthy for Sensitive Groups 2 of 348 days2017: Good 309 of 354 days2017: Moderate 45 of 354 days2018: Good 309 of 343 days2018: Moderate 34 of 343 days2019: Good 325 of 361 days2019: Moderate 36 of 361 days2020: Good 331 of 356 days2020: Moderate 25 of 356 days20202021: Good 307 of 351 days2021: Moderate 44 of 351 days2022: Good 319 of 353 days2022: Moderate 34 of 353 days2023: Good 307 of 352 days2023: Moderate 42 of 352 days2023: Unhealthy for Sensitive Groups 2 of 352 days2023: Very Unhealthy 1 of 352 days2024: Good 290 of 357 days2024: Moderate 67 of 357 days2025: Good 311 of 362 days2025: Moderate 51 of 362 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 year0501001501985: 90th percentile AQI 541986: 90th percentile AQI 521987: 90th percentile AQI 521988: 90th percentile AQI 441989: 90th percentile AQI 521990: 90th percentile AQI 521991: 90th percentile AQI 531992: 90th percentile AQI 531993: 90th percentile AQI 451994: 90th percentile AQI 1081995: 90th percentile AQI 1191996: 90th percentile AQI 771997: 90th percentile AQI 1011998: 90th percentile AQI 1191999: 90th percentile AQI 1012000: 90th percentile AQI 932001: 90th percentile AQI 972002: 90th percentile AQI 852003: 90th percentile AQI 742004: 90th percentile AQI 672005: 90th percentile AQI 902006: 90th percentile AQI 692007: 90th percentile AQI 802008: 90th percentile AQI 642009: 90th percentile AQI 632010: 90th percentile AQI 772011: 90th percentile AQI 602012: 90th percentile AQI 712013: 90th percentile AQI 582014: 90th percentile AQI 612015: 90th percentile AQI 582016: 90th percentile AQI 542017: 90th percentile AQI 522018: 90th percentile AQI 502019: 90th percentile AQI 502020: 90th percentile AQI 472021: 90th percentile AQI 532022: 90th percentile AQI 502023: 90th percentile AQI 542024: 90th percentile AQI 642025: 90th percentile AQI 541985: Median AQI 401986: Median AQI 311987: Median AQI 301988: Median AQI 241989: Median AQI 301990: Median AQI 251991: Median AQI 291992: Median AQI 281993: Median AQI 251994: Median AQI 371995: Median AQI 391996: Median AQI 281997: Median AQI 411998: Median AQI 401999: Median AQI 402000: Median AQI 402001: Median AQI 422002: Median AQI 412003: Median AQI 412004: Median AQI 392005: Median AQI 432006: Median AQI 402007: Median AQI 432008: Median AQI 412009: Median AQI 402010: Median AQI 432011: Median AQI 412012: Median AQI 412013: Median AQI 382014: Median AQI 392015: Median AQI 382016: Median AQI 392017: Median AQI 382018: Median AQI 362019: Median AQI 382020: Median AQI 362021: Median AQI 372022: Median AQI 372023: Median AQI 392024: Median AQI 402025: Median AQI 37198519901995200020052010201520202025
  • 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
Ozone33492%
Fine particles (PM2.5)288%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025362311510000375490Ozone
2024357290670000406490Ozone
20233523074220103954207Ozone
2022353319340000375093Ozone
2021351307440000375384Ozone
2020356331250000364787Ozone
2019361325360000385087Ozone
2018343309340000365097Ozone
2017354309450000385297Ozone
20163482974920003954105Ozone
20153602966310003858112Ozone
20143552856910003961112Ozone
20133482856210003858108Ozone
20123232388050004171115Ozone
2011304243610000416097Ozone
201034023296120004377136Ozone
20093532737820004063105Ozone
20083602748330004164126Ozone
200736324799170004380143Ozone
20063392528340004069133Ozone
2005355228102241004390154Ozone
20043572589360003967132Ozone
200335824110772104174213Ozone
200225416476104004185192Ozone
200136323398275004297174Ozone
200035325280192004093172Ozone
19993412416524101040101204Ozone
19983452127737172040119204Ozone
1997338243613040041101177Ozone
19961521291571002877179Ozone
19953171977728132039119222Ozone
1994353248594060037108161Ozone
1993135129600002545100Ozone
1992605280000285364PM10
19916053610002953107PM10
1990564970000255258PM10
1989534670000305265PM10
1988605640000244465PM10
1987605190000305297PM10
1986494360000315257PM10
1985181440000405457PM10

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 1985–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem