EnviroNearby

Perry County, Indiana air quality history

Daily Air Quality Index summaries from EPA monitors in Perry, Indiana, 1997–2025.

93%
Good days in 2025
36
Median daily AQI, 2025
0
Days above 100 in 2025
317
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Perry, Indiana on 317 days. 294 of those days (93%) were in the Good range, and the median daily AQI was 36. 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 317 days. Across the years with fuller monitoring, the share of Good days rose: an average of 55% in 1998–2000 versus 89% in 2023–2025.

Years with fewer than 120 monitored days (1997, 2002, 2003) 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%1997: Good 39 of 44 days1997: Moderate 5 of 44 days19971998: Good 64 of 125 days1998: Moderate 30 of 125 days1998: Unhealthy for Sensitive Groups 15 of 125 days1998: Unhealthy 15 of 125 days1998: Very Unhealthy 1 of 125 days1999: Good 114 of 205 days1999: Moderate 51 of 205 days1999: Unhealthy for Sensitive Groups 25 of 205 days1999: Unhealthy 15 of 205 days2000: Good 122 of 212 days2000: Moderate 59 of 212 days2000: Unhealthy for Sensitive Groups 25 of 212 days2000: Unhealthy 6 of 212 days2001: Good 110 of 213 days2001: Moderate 71 of 213 days2001: Unhealthy for Sensitive Groups 28 of 213 days2001: Unhealthy 4 of 213 days2002: Good 54 of 61 days2002: Moderate 7 of 61 days20022003: Good 58 of 60 days2003: Moderate 2 of 60 days2004: Good 135 of 212 days2004: Moderate 68 of 212 days2004: Unhealthy for Sensitive Groups 9 of 212 days2005: Good 100 of 209 days2005: Moderate 70 of 209 days2005: Unhealthy for Sensitive Groups 35 of 209 days2005: Unhealthy 4 of 209 days2006: Good 121 of 214 days2006: Moderate 79 of 214 days2006: Unhealthy for Sensitive Groups 14 of 214 days2007: Good 117 of 213 days2007: Moderate 71 of 213 days2007: Unhealthy for Sensitive Groups 23 of 213 days2007: Unhealthy 2 of 213 days20072008: Good 153 of 211 days2008: Moderate 53 of 211 days2008: Unhealthy for Sensitive Groups 5 of 211 days2009: Good 169 of 198 days2009: Moderate 28 of 198 days2009: Unhealthy for Sensitive Groups 1 of 198 days2010: Good 110 of 183 days2010: Moderate 67 of 183 days2010: Unhealthy for Sensitive Groups 6 of 183 days2011: Good 129 of 182 days2011: Moderate 44 of 182 days2011: Unhealthy for Sensitive Groups 9 of 182 days2012: Good 96 of 183 days2012: Moderate 66 of 183 days2012: Unhealthy for Sensitive Groups 19 of 183 days2012: Unhealthy 2 of 183 days20122013: Good 151 of 183 days2013: Moderate 32 of 183 days2014: Good 131 of 175 days2014: Moderate 43 of 175 days2014: Unhealthy for Sensitive Groups 1 of 175 days2015: Good 147 of 183 days2015: Moderate 34 of 183 days2015: Unhealthy for Sensitive Groups 2 of 183 days2016: Good 140 of 183 days2016: Moderate 40 of 183 days2016: Unhealthy for Sensitive Groups 3 of 183 days2017: Good 212 of 243 days2017: Moderate 30 of 243 days2017: Unhealthy for Sensitive Groups 1 of 243 days20172018: Good 324 of 350 days2018: Moderate 26 of 350 days2019: Good 322 of 358 days2019: Moderate 36 of 358 days2020: Good 352 of 366 days2020: Moderate 13 of 366 days2020: Unhealthy for Sensitive Groups 1 of 366 days2021: Good 334 of 363 days2021: Moderate 29 of 363 days2022: Good 344 of 365 days2022: Moderate 20 of 365 days2022: Unhealthy for Sensitive Groups 1 of 365 days20222023: Good 318 of 357 days2023: Moderate 37 of 357 days2023: Unhealthy for Sensitive Groups 2 of 357 days2024: Good 286 of 330 days2024: Moderate 44 of 330 days2025: Good 294 of 317 days2025: Moderate 23 of 317 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 year0501001502001997: 90th percentile AQI 531998: 90th percentile AQI 1541999: 90th percentile AQI 1432000: 90th percentile AQI 1082001: 90th percentile AQI 1082002: 90th percentile AQI 522003: 90th percentile AQI 432004: 90th percentile AQI 842005: 90th percentile AQI 1122006: 90th percentile AQI 972007: 90th percentile AQI 1052008: 90th percentile AQI 742009: 90th percentile AQI 582010: 90th percentile AQI 932011: 90th percentile AQI 842012: 90th percentile AQI 1082013: 90th percentile AQI 582014: 90th percentile AQI 642015: 90th percentile AQI 672016: 90th percentile AQI 742017: 90th percentile AQI 542018: 90th percentile AQI 502019: 90th percentile AQI 512020: 90th percentile AQI 452021: 90th percentile AQI 502022: 90th percentile AQI 482023: 90th percentile AQI 512024: 90th percentile AQI 512025: 90th percentile AQI 491997: Median AQI 241998: Median AQI 491999: Median AQI 442000: Median AQI 472001: Median AQI 492002: Median AQI 202003: Median AQI 232004: Median AQI 472005: Median AQI 542006: Median AQI 472007: Median AQI 482008: Median AQI 432009: Median AQI 412010: Median AQI 482011: Median AQI 452012: Median AQI 492013: Median AQI 422014: Median AQI 452015: Median AQI 432016: Median AQI 412017: Median AQI 402018: Median AQI 352019: Median AQI 372020: Median AQI 342021: Median AQI 362022: Median AQI 362023: Median AQI 382024: Median AQI 392025: Median AQI 361997200220072012201720222025
  • 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
Ozone317100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025317294230000364984Ozone
2024330286440000395190Ozone
20233573183720003851112Ozone
20223653442010003648119Ozone
2021363334290000365097Ozone
20203663521310003445105Ozone
2019358322360000375180Ozone
2018350324260000355080Ozone
20172432123010004054101Ozone
20161831404030004174136Ozone
20151831473420004367112Ozone
20141751314310004564101Ozone
20131831513200004258100Ozone
201218396661920049108166Ozone
20111821294490004584133Ozone
20101831106760004893122Ozone
20091981692810004158119Ozone
20082111535350004374133Ozone
2007213117712320048105166Ozone
200621412179140004797147Ozone
2005209100703540054112156Ozone
20042121356890004784136Ozone
2003605820000234352PM10
2002615470000205288PM10
2001213110712840049108182Ozone
2000212122592560047108172Ozone
19992051145125150044143200Ozone
1998125643015151049154201Ozone
1997443950000245356PM10

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 1997–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem