EnviroNearby

Whitley County, Indiana air quality history

Daily Air Quality Index summaries from EPA monitors in Whitley, Indiana, 2001–2025.

64%
Good days in 2025
39
Median daily AQI, 2025
2
Days above 100 in 2025
363
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Whitley, Indiana on 363 days. 233 of those days (64%) were in the Good range, and the median daily AQI was 39. That median is about the same as the typical monitored county in Indiana (median 41 across 33 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 363 days. Across the years with fuller monitoring, the share of Good days rose: an average of 50% in 2010–2012 versus 65% in 2023–2025.

Years with fewer than 120 monitored days (2004, 2005, 2006, 2007, 2008, 2009…) 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%2001: Good 10 of 10 days20012002: Good 52 of 59 days2002: Moderate 7 of 59 days2003: Good 57 of 62 days2003: Moderate 5 of 62 days20032004: Good 53 of 59 days2004: Moderate 6 of 59 days2005: Good 46 of 58 days2005: Moderate 12 of 58 days20052006: Good 49 of 59 days2006: Moderate 10 of 59 days2007: Good 34 of 55 days2007: Moderate 21 of 55 days20072008: Good 41 of 61 days2008: Moderate 19 of 61 days2008: Unhealthy for Sensitive Groups 1 of 61 days2009: Good 55 of 60 days2009: Moderate 5 of 60 days20092010: Good 125 of 249 days2010: Moderate 123 of 249 days2010: Unhealthy for Sensitive Groups 1 of 249 days2011: Good 142 of 348 days2011: Moderate 206 of 348 days20112012: Good 179 of 307 days2012: Moderate 127 of 307 days2012: Unhealthy for Sensitive Groups 1 of 307 days2013: Good 130 of 360 days2013: Moderate 229 of 360 days2013: Unhealthy for Sensitive Groups 1 of 360 days20132014: Good 173 of 356 days2014: Moderate 181 of 356 days2014: Unhealthy for Sensitive Groups 2 of 356 days2015: Good 170 of 359 days2015: Moderate 189 of 359 days20152016: Good 240 of 356 days2016: Moderate 116 of 356 days2017: Good 223 of 350 days2017: Moderate 127 of 350 days20172018: Good 235 of 348 days2018: Moderate 113 of 348 days2019: Good 213 of 352 days2019: Moderate 139 of 352 days20192020: Good 160 of 336 days2020: Moderate 176 of 336 days2021: Good 203 of 361 days2021: Moderate 158 of 361 days20212022: Good 221 of 360 days2022: Moderate 138 of 360 days2022: Unhealthy for Sensitive Groups 1 of 360 days2023: Good 195 of 363 days2023: Moderate 161 of 363 days2023: Unhealthy for Sensitive Groups 4 of 363 days2023: Unhealthy 2 of 363 days2023: Very Unhealthy 1 of 363 days20232024: Good 278 of 366 days2024: Moderate 88 of 366 days2025: Good 233 of 363 days2025: Moderate 128 of 363 days2025: Unhealthy for Sensitive Groups 2 of 363 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 year0501002001: 90th percentile AQI 372002: 90th percentile AQI 522003: 90th percentile AQI 482004: 90th percentile AQI 512005: 90th percentile AQI 592006: 90th percentile AQI 582007: 90th percentile AQI 722008: 90th percentile AQI 692009: 90th percentile AQI 492010: 90th percentile AQI 722011: 90th percentile AQI 702012: 90th percentile AQI 672013: 90th percentile AQI 702014: 90th percentile AQI 692015: 90th percentile AQI 662016: 90th percentile AQI 582017: 90th percentile AQI 602018: 90th percentile AQI 592019: 90th percentile AQI 602020: 90th percentile AQI 612021: 90th percentile AQI 642022: 90th percentile AQI 632023: 90th percentile AQI 662024: 90th percentile AQI 562025: 90th percentile AQI 612001: Median AQI 172002: Median AQI 192003: Median AQI 302004: Median AQI 272005: Median AQI 272006: Median AQI 212007: Median AQI 422008: Median AQI 352009: Median AQI 212010: Median AQI 502011: Median AQI 532012: Median AQI 442013: Median AQI 542014: Median AQI 512015: Median AQI 512016: Median AQI 402017: Median AQI 442018: Median AQI 412019: Median AQI 432020: Median AQI 512021: Median AQI 472022: Median AQI 442023: Median AQI 482024: Median AQI 352025: Median AQI 392001200320052007200920112013201520172019202120232025
  • 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
Fine particles (PM2.5)363100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536323312820003961108PM2.5
2024366278880000355670PM2.5
202336319516142104866223PM2.5
202236022113810004463109PM2.5
20213612031580000476496PM2.5
20203361601760000516179PM2.5
20193522131390000436091PM2.5
20183482351130000415984PM2.5
20173502231270000446087PM2.5
20163562401160000405879PM2.5
20153591701890000516689PM2.5
201435617318120005169125PM2.5
201336013022910005470104PM2.5
201230717912710004467106PM2.5
20113481422060000537089PM2.5
201024912512310005072102PM2.5
2009605550000214966PM10
200861411910003569142PM10
20075534210000427299PM10
20065949100000215876PM10
20055846120000275973PM10
2004595360000275164PM10
2003625750000304859PM10
2002595270000195278PM10
2001101000000173737PM10

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 2001–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem