EnviroNearby

Columbiana County, Ohio air quality history

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

92%
Good days in 1998
27
Median daily AQI, 1998
0
Days above 100 in 1998
298
Days with an AQI in 1998 (of 365)

In 1998, EPA reported a daily Air Quality Index (AQI) for Columbiana, Ohio on 298 days. 274 of those days (92%) were in the Good range, and the median daily AQI was 27. That median is lower than the typical monitored county in Ohio (median 45.5 across 42 counties), and lower than the typical monitored U.S. county (41). The main pollutant was nitrogen dioxide (NO₂) on 230 days. Across the years with fuller monitoring, the share of Good days rose: an average of 81% in 1985–1987 versus 92% in 1996–1998.

EPA did not report an AQI for every day of 1998 here (298 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 (2020, 2021, 2022, 2023, 2024, 2025…) 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 100 of 121 days1985: Moderate 21 of 121 days19851986: Good 136 of 175 days1986: Moderate 39 of 175 days1987: Good 149 of 182 days1987: Moderate 33 of 182 days1988: Good 151 of 182 days1988: Moderate 31 of 182 days1989: Good 152 of 180 days1989: Moderate 28 of 180 days1990: Good 154 of 178 days1990: Moderate 24 of 178 days19901991: Good 218 of 255 days1991: Moderate 37 of 255 days1992: Good 312 of 365 days1992: Moderate 53 of 365 days1993: Good 239 of 362 days1993: Moderate 104 of 362 days1993: Unhealthy for Sensitive Groups 19 of 362 days1994: Good 257 of 365 days1994: Moderate 94 of 365 days1994: Unhealthy for Sensitive Groups 14 of 365 days1995: Good 298 of 362 days1995: Moderate 64 of 362 days19951996: Good 315 of 352 days1996: Moderate 37 of 352 days1997: Good 310 of 327 days1997: Moderate 17 of 327 days1998: Good 274 of 298 days1998: Moderate 24 of 298 days1999: Good 37 of 56 days1999: Moderate 18 of 56 days1999: Unhealthy for Sensitive Groups 1 of 56 days2000: Good 38 of 47 days2000: Moderate 9 of 47 days20002001: Good 16 of 17 days2001: Moderate 1 of 17 days2002: Good 17 of 18 days2002: Moderate 1 of 18 days2003: Good 52 of 61 days2003: Moderate 9 of 61 days2004: Good 54 of 61 days2004: Moderate 7 of 61 days2005: Good 55 of 61 days2005: Moderate 6 of 61 days20052006: Good 58 of 61 days2006: Moderate 3 of 61 days2007: Good 56 of 59 days2007: Moderate 3 of 59 days2008: Good 59 of 61 days2008: Moderate 2 of 61 days2009: Good 60 of 61 days2009: Moderate 1 of 61 days2010: Good 59 of 61 days2010: Moderate 2 of 61 days20102011: Good 61 of 61 days2012: Good 61 of 61 days2013: Good 61 of 61 days2014: Good 61 of 61 days2015: Good 60 of 60 days20152016: Good 61 of 61 days2017: Good 61 of 61 days2018: Good 63 of 63 days2019: Good 62 of 62 days2020: Good 48 of 48 days20202021: Good 61 of 61 days2022: Good 61 of 61 days2023: Good 60 of 61 days2023: Moderate 1 of 61 days2024: Good 63 of 63 days2025: Good 61 of 61 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 year0501001985: 90th percentile AQI 581986: 90th percentile AQI 561987: 90th percentile AQI 561988: 90th percentile AQI 541989: 90th percentile AQI 571990: 90th percentile AQI 521991: 90th percentile AQI 531992: 90th percentile AQI 531993: 90th percentile AQI 831994: 90th percentile AQI 781995: 90th percentile AQI 561996: 90th percentile AQI 511997: 90th percentile AQI 431998: 90th percentile AQI 481999: 90th percentile AQI 672000: 90th percentile AQI 732001: 90th percentile AQI 482002: 90th percentile AQI 352003: 90th percentile AQI 542004: 90th percentile AQI 522005: 90th percentile AQI 502006: 90th percentile AQI 452007: 90th percentile AQI 452008: 90th percentile AQI 402009: 90th percentile AQI 362010: 90th percentile AQI 362011: 90th percentile AQI 322012: 90th percentile AQI 272013: 90th percentile AQI 262014: 90th percentile AQI 292015: 90th percentile AQI 302016: 90th percentile AQI 242017: 90th percentile AQI 202018: 90th percentile AQI 212019: 90th percentile AQI 222020: 90th percentile AQI 202021: 90th percentile AQI 242022: 90th percentile AQI 232023: 90th percentile AQI 262024: 90th percentile AQI 192025: 90th percentile AQI 221985: Median AQI 301986: Median AQI 331987: Median AQI 331988: Median AQI 311989: Median AQI 321990: Median AQI 281991: Median AQI 281992: Median AQI 331993: Median AQI 401994: Median AQI 351995: Median AQI 381996: Median AQI 321997: Median AQI 271998: Median AQI 271999: Median AQI 342000: Median AQI 312001: Median AQI 262002: Median AQI 252003: Median AQI 302004: Median AQI 242005: Median AQI 262006: Median AQI 262007: Median AQI 242008: Median AQI 212009: Median AQI 232010: Median AQI 232011: Median AQI 202012: Median AQI 192013: Median AQI 172014: Median AQI 162015: Median AQI 182016: Median AQI 152017: Median AQI 142018: Median AQI 122019: Median AQI 122020: Median AQI 102021: Median AQI 162022: Median AQI 122023: Median AQI 112024: Median AQI 122025: Median AQI 12198519901995200020052010201520202025
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 1998

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
Nitrogen dioxide (NO₂)23077%
Coarse particles (PM10)6823%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025616100000122231PM10
2024636300000121934PM10
2023616010000112674PM10
2022616100000122340PM10
2021616100000162435PM10
2020484800000102031PM10
2019626200000122226PM10
2018636300000122130PM10
2017616100000142026PM10
2016616100000152436PM10
2015606000000183050PM10
2014616100000162935PM10
2013616100000172643PM10
2012616100000192737PM10
2011616100000203237PM10
2010615920000233658PM10
2009616010000233657PM10
2008615920000214058PM10
2007595630000244554PM10
2006615830000264564PM10
2005615560000265073PM10
2004615470000245266PM10
2003615290000305471PM10
2002181710000253568PM10
2001171610000264853PM10
2000473890000317388PM10
199956371810003467110PM10
1998298274240000274884NO2
1997327310170000274373NO2
1996352315370000325187NO2
1995362298640000385688NO2
199436525794140003578149NO2
1993362239104190004083113NO2
1992365312530000335398NO2
1991255218370000285382PM10
1990178154240000285282PM10
1989180152280000325786PM10
1988182151310000315475PM10
1987182149330000335683PM10
1986175136390000335687PM10
1985121100210000305882PM10

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.

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