EnviroNearby

Shelby County, Indiana air quality history

Daily Air Quality Index summaries from EPA monitors in Shelby, Indiana, 2000–2025.

91%
Good days in 2025
35
Median daily AQI, 2025
1
Days above 100 in 2025
359
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Shelby, Indiana on 359 days. 328 of those days (91%) were in the Good range, and the median daily AQI was 35. That median is lower than the typical monitored county in Indiana (median 41 across 33 counties), and lower than the typical monitored U.S. county (40). The main pollutant was ozone on 359 days. Across the years with fuller monitoring, the share of Good days rose: an average of 49% in 2000–2002 versus 90% 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%2000: Good 100 of 182 days2000: Moderate 64 of 182 days2000: Unhealthy for Sensitive Groups 14 of 182 days2000: Unhealthy 4 of 182 days20002001: Good 82 of 183 days2001: Moderate 68 of 183 days2001: Unhealthy for Sensitive Groups 27 of 183 days2001: Unhealthy 6 of 183 days2002: Good 85 of 183 days2002: Moderate 62 of 183 days2002: Unhealthy for Sensitive Groups 23 of 183 days2002: Unhealthy 12 of 183 days2002: Very Unhealthy 1 of 183 days20022003: Good 99 of 183 days2003: Moderate 63 of 183 days2003: Unhealthy for Sensitive Groups 17 of 183 days2003: Unhealthy 4 of 183 days2004: Good 124 of 183 days2004: Moderate 55 of 183 days2004: Unhealthy for Sensitive Groups 4 of 183 days20042005: Good 97 of 183 days2005: Moderate 66 of 183 days2005: Unhealthy for Sensitive Groups 20 of 183 days2006: Good 120 of 181 days2006: Moderate 54 of 181 days2006: Unhealthy for Sensitive Groups 7 of 181 days20062007: Good 83 of 182 days2007: Moderate 66 of 182 days2007: Unhealthy for Sensitive Groups 32 of 182 days2007: Unhealthy 1 of 182 days2008: Good 126 of 182 days2008: Moderate 54 of 182 days2008: Unhealthy for Sensitive Groups 2 of 182 days20082009: Good 128 of 183 days2009: Moderate 46 of 183 days2009: Unhealthy for Sensitive Groups 8 of 183 days2009: Unhealthy 1 of 183 days2010: Good 130 of 181 days2010: Moderate 51 of 181 days20102011: Good 114 of 179 days2011: Moderate 57 of 179 days2011: Unhealthy for Sensitive Groups 8 of 179 days2012: Good 95 of 183 days2012: Moderate 70 of 183 days2012: Unhealthy for Sensitive Groups 16 of 183 days2012: Unhealthy 2 of 183 days20122013: Good 148 of 183 days2013: Moderate 35 of 183 days2014: Good 157 of 182 days2014: Moderate 25 of 182 days20142015: Good 166 of 183 days2015: Moderate 17 of 183 days2016: Good 153 of 183 days2016: Moderate 29 of 183 days2016: Unhealthy for Sensitive Groups 1 of 183 days20162017: Good 209 of 243 days2017: Moderate 33 of 243 days2017: Unhealthy for Sensitive Groups 1 of 243 days2018: Good 331 of 361 days2018: Moderate 25 of 361 days2018: Unhealthy for Sensitive Groups 5 of 361 days20182019: Good 338 of 365 days2019: Moderate 27 of 365 days2020: Good 347 of 366 days2020: Moderate 18 of 366 days2020: Unhealthy for Sensitive Groups 1 of 366 days20202021: Good 345 of 365 days2021: Moderate 20 of 365 days2022: Good 336 of 364 days2022: Moderate 26 of 364 days2022: Unhealthy for Sensitive Groups 2 of 364 days20222023: Good 317 of 359 days2023: Moderate 38 of 359 days2023: Unhealthy for Sensitive Groups 4 of 359 days2024: Good 331 of 365 days2024: Moderate 34 of 365 days20242025: Good 328 of 359 days2025: Moderate 30 of 359 days2025: Unhealthy for Sensitive Groups 1 of 359 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 year0501001502000: 90th percentile AQI 1002001: 90th percentile AQI 1222002: 90th percentile AQI 1262003: 90th percentile AQI 1052004: 90th percentile AQI 802005: 90th percentile AQI 1012006: 90th percentile AQI 772007: 90th percentile AQI 1192008: 90th percentile AQI 772009: 90th percentile AQI 712010: 90th percentile AQI 742011: 90th percentile AQI 842012: 90th percentile AQI 1002013: 90th percentile AQI 612014: 90th percentile AQI 582015: 90th percentile AQI 492016: 90th percentile AQI 612017: 90th percentile AQI 582018: 90th percentile AQI 492019: 90th percentile AQI 492020: 90th percentile AQI 462021: 90th percentile AQI 462022: 90th percentile AQI 492023: 90th percentile AQI 582024: 90th percentile AQI 502025: 90th percentile AQI 492000: Median AQI 492001: Median AQI 542002: Median AQI 582003: Median AQI 492004: Median AQI 452005: Median AQI 502006: Median AQI 452007: Median AQI 542008: Median AQI 462009: Median AQI 442010: Median AQI 442011: Median AQI 462012: Median AQI 492013: Median AQI 442014: Median AQI 422015: Median AQI 392016: Median AQI 392017: Median AQI 412018: Median AQI 342019: Median AQI 362020: Median AQI 322021: Median AQI 332022: Median AQI 362023: Median AQI 372024: Median AQI 362025: Median AQI 3520002002200420062008201020122014201620182020202220242025
  • 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
Ozone359100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253593283010003549105Ozone
2024365331340000365087Ozone
20233593173840003758147Ozone
20223643362620003649115Ozone
20213653452000003346100Ozone
20203663471810003246115Ozone
2019365338270000364984Ozone
20183613312550003449112Ozone
20172432093310004158108Ozone
20161831532910003961101Ozone
2015183166170000394977Ozone
20141821572500004258100Ozone
2013183148350000446197Ozone
201218395701620049100159Ozone
20111791145780004684143Ozone
2010181130510000447493Ozone
20091831284681004471151Ozone
20081821265420004677101Ozone
200718283663210054119161Ozone
20061811205470004577129Ozone
200518397662000050101147Ozone
20041831245540004580129Ozone
200318399631740049105179Ozone
2002183856223121058126213Ozone
200118382682760054122182Ozone
2000182100641440049100179Ozone

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 Indiana with a similar median AQI in 2025

All monitored counties in Indiana

Source: U.S. EPA AirData, “Annual AQI by County” files for 2000–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem