EnviroNearby

Anderson County, Tennessee air quality history

Daily Air Quality Index summaries from EPA monitors in Anderson, Tennessee, 1992–2025.

94%
Good days in 2025
39
Median daily AQI, 2025
1
Days above 100 in 2025
244
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Anderson, Tennessee on 244 days. 230 of those days (94%) were in the Good range, and the median daily AQI was 39. That median is about the same as the typical monitored county in Tennessee (median 39 across 23 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 244 days. Across the years with fuller monitoring, the share of Good days rose: an average of 56% in 1992–1994 versus 92% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (244 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.

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%1992: Good 154 of 212 days1992: Moderate 45 of 212 days1992: Unhealthy for Sensitive Groups 11 of 212 days1992: Unhealthy 2 of 212 days19921993: Good 87 of 208 days1993: Moderate 85 of 208 days1993: Unhealthy for Sensitive Groups 31 of 208 days1993: Unhealthy 5 of 208 days1994: Good 109 of 206 days1994: Moderate 61 of 206 days1994: Unhealthy for Sensitive Groups 31 of 206 days1994: Unhealthy 5 of 206 days1995: Good 79 of 194 days1995: Moderate 69 of 194 days1995: Unhealthy for Sensitive Groups 35 of 194 days1995: Unhealthy 11 of 194 days1996: Good 97 of 213 days1996: Moderate 79 of 213 days1996: Unhealthy for Sensitive Groups 35 of 213 days1996: Unhealthy 2 of 213 days1997: Good 111 of 210 days1997: Moderate 69 of 210 days1997: Unhealthy for Sensitive Groups 27 of 210 days1997: Unhealthy 3 of 210 days19971998: Good 84 of 190 days1998: Moderate 63 of 190 days1998: Unhealthy for Sensitive Groups 34 of 190 days1998: Unhealthy 9 of 190 days1999: Good 100 of 240 days1999: Moderate 69 of 240 days1999: Unhealthy for Sensitive Groups 57 of 240 days1999: Unhealthy 14 of 240 days2000: Good 118 of 222 days2000: Moderate 67 of 222 days2000: Unhealthy for Sensitive Groups 30 of 222 days2000: Unhealthy 7 of 222 days2001: Good 140 of 240 days2001: Moderate 76 of 240 days2001: Unhealthy for Sensitive Groups 21 of 240 days2001: Unhealthy 3 of 240 days2002: Good 133 of 234 days2002: Moderate 51 of 234 days2002: Unhealthy for Sensitive Groups 33 of 234 days2002: Unhealthy 16 of 234 days2002: Very Unhealthy 1 of 234 days20022003: Good 171 of 237 days2003: Moderate 56 of 237 days2003: Unhealthy for Sensitive Groups 8 of 237 days2003: Unhealthy 2 of 237 days2004: Good 173 of 240 days2004: Moderate 64 of 240 days2004: Unhealthy for Sensitive Groups 3 of 240 days2005: Good 143 of 241 days2005: Moderate 75 of 241 days2005: Unhealthy for Sensitive Groups 21 of 241 days2005: Unhealthy 2 of 241 days2006: Good 147 of 245 days2006: Moderate 78 of 245 days2006: Unhealthy for Sensitive Groups 18 of 245 days2006: Unhealthy 1 of 245 days2006: Very Unhealthy 1 of 245 days2007: Good 110 of 238 days2007: Moderate 102 of 238 days2007: Unhealthy for Sensitive Groups 25 of 238 days2007: Unhealthy 1 of 238 days20072008: Good 165 of 240 days2008: Moderate 68 of 240 days2008: Unhealthy for Sensitive Groups 6 of 240 days2008: Unhealthy 1 of 240 days2009: Good 204 of 242 days2009: Moderate 38 of 242 days2010: Good 168 of 244 days2010: Moderate 69 of 244 days2010: Unhealthy for Sensitive Groups 7 of 244 days2011: Good 176 of 238 days2011: Moderate 54 of 238 days2011: Unhealthy for Sensitive Groups 8 of 238 days2012: Good 136 of 194 days2012: Moderate 54 of 194 days2012: Unhealthy for Sensitive Groups 3 of 194 days2012: Unhealthy 1 of 194 days20122013: Good 221 of 237 days2013: Moderate 16 of 237 days2014: Good 210 of 233 days2014: Moderate 23 of 233 days2015: Good 216 of 240 days2015: Moderate 24 of 240 days2016: Good 185 of 223 days2016: Moderate 38 of 223 days2017: Good 214 of 245 days2017: Moderate 31 of 245 days20172018: Good 196 of 229 days2018: Moderate 33 of 229 days2019: Good 177 of 234 days2019: Moderate 55 of 234 days2019: Unhealthy for Sensitive Groups 2 of 234 days2020: Good 238 of 245 days2020: Moderate 7 of 245 days2021: Good 219 of 235 days2021: Moderate 16 of 235 days2022: Good 228 of 245 days2022: Moderate 17 of 245 days20222023: Good 212 of 237 days2023: Moderate 24 of 237 days2023: Unhealthy for Sensitive Groups 1 of 237 days2024: Good 221 of 243 days2024: Moderate 22 of 243 days2025: Good 230 of 244 days2025: Moderate 13 of 244 days2025: Unhealthy for Sensitive Groups 1 of 244 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 year0501001501992: 90th percentile AQI 801993: 90th percentile AQI 1221994: 90th percentile AQI 1191995: 90th percentile AQI 1401996: 90th percentile AQI 1121997: 90th percentile AQI 1151998: 90th percentile AQI 1361999: 90th percentile AQI 1402000: 90th percentile AQI 1262001: 90th percentile AQI 1012002: 90th percentile AQI 1362003: 90th percentile AQI 872004: 90th percentile AQI 742005: 90th percentile AQI 1002006: 90th percentile AQI 972007: 90th percentile AQI 1012008: 90th percentile AQI 802009: 90th percentile AQI 582010: 90th percentile AQI 842011: 90th percentile AQI 772012: 90th percentile AQI 742013: 90th percentile AQI 492014: 90th percentile AQI 502015: 90th percentile AQI 512016: 90th percentile AQI 612017: 90th percentile AQI 542018: 90th percentile AQI 612019: 90th percentile AQI 712020: 90th percentile AQI 462021: 90th percentile AQI 492022: 90th percentile AQI 482023: 90th percentile AQI 512024: 90th percentile AQI 502025: 90th percentile AQI 481992: Median AQI 421993: Median AQI 611994: Median AQI 491995: Median AQI 581996: Median AQI 511997: Median AQI 491998: Median AQI 581999: Median AQI 642000: Median AQI 502001: Median AQI 482002: Median AQI 492003: Median AQI 422004: Median AQI 442005: Median AQI 482006: Median AQI 472007: Median AQI 542008: Median AQI 462009: Median AQI 382010: Median AQI 442011: Median AQI 442012: Median AQI 442013: Median AQI 382014: Median AQI 382015: Median AQI 392016: Median AQI 432017: Median AQI 402018: Median AQI 402019: Median AQI 442020: Median AQI 352021: Median AQI 382022: Median AQI 392023: Median AQI 412024: Median AQI 412025: Median AQI 3919921997200220072012201720222025
  • 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
Ozone244100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20252442301310003948105Ozone
20242432212200004150100Ozone
20232372122410004151105Ozone
2022245228170000394880Ozone
2021235219160000384987Ozone
202024523870000354664Ozone
20192341775520004471105Ozone
2018229196330000406190Ozone
2017245214310000405490Ozone
2016223185380000436193Ozone
2015240216240000395197Ozone
2014233210230000385087Ozone
2013237221160000384977Ozone
20121941365431004474161Ozone
20112381765480004477122Ozone
20102441686970004484126Ozone
2009242204380000385893Ozone
20082401656861004680151Ozone
20072381101022510054101161Ozone
200624514778181104797202Ozone
2005241143752120048100161Ozone
20042401736430004474126Ozone
20032371715682004287169Ozone
20022341335133161049136202Ozone
2001240140762130048101177Ozone
2000222118673070050126182Ozone
19992401006957140064140190Ozone
199819084633490058136164Ozone
1997210111692730049115151Ozone
199621397793520051112174Ozone
1995194796935110058140187Ozone
1994206109613150049119190Ozone
199320887853150061122172Ozone
199221215445112004280156Ozone

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 Tennessee with a similar median AQI in 2025

All monitored counties in Tennessee

Source: U.S. EPA AirData, “Annual AQI by County” files for 1992–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem