EnviroNearby

Lenoir County, North Carolina air quality history

Daily Air Quality Index summaries from EPA monitors in Lenoir, North Carolina, 1998–2025.

98%
Good days in 2025
35
Median daily AQI, 2025
0
Days above 100 in 2025
245
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Lenoir, North Carolina on 245 days. 239 of those days (98%) were in the Good range, and the median daily AQI was 35. That median is lower than the typical monitored county in North Carolina (median 39 across 33 counties), and lower than the typical monitored U.S. county (40). The main pollutant was ozone on 245 days. Across the years with fuller monitoring, the share of Good days rose: an average of 48% in 1998–2000 versus 94% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (245 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%1998: Good 102 of 214 days1998: Moderate 76 of 214 days1998: Unhealthy for Sensitive Groups 29 of 214 days1998: Unhealthy 7 of 214 days19981999: Good 126 of 249 days1999: Moderate 93 of 249 days1999: Unhealthy for Sensitive Groups 24 of 249 days1999: Unhealthy 6 of 249 days2000: Good 119 of 263 days2000: Moderate 123 of 263 days2000: Unhealthy for Sensitive Groups 19 of 263 days2000: Unhealthy 2 of 263 days20002001: Good 141 of 264 days2001: Moderate 105 of 264 days2001: Unhealthy for Sensitive Groups 17 of 264 days2001: Unhealthy 1 of 264 days2002: Good 122 of 260 days2002: Moderate 115 of 260 days2002: Unhealthy for Sensitive Groups 20 of 260 days2002: Unhealthy 3 of 260 days20022003: Good 144 of 256 days2003: Moderate 103 of 256 days2003: Unhealthy for Sensitive Groups 6 of 256 days2003: Unhealthy 3 of 256 days2004: Good 146 of 253 days2004: Moderate 104 of 253 days2004: Unhealthy for Sensitive Groups 3 of 253 days20042005: Good 129 of 255 days2005: Moderate 107 of 255 days2005: Unhealthy for Sensitive Groups 17 of 255 days2005: Unhealthy 2 of 255 days2006: Good 138 of 257 days2006: Moderate 112 of 257 days2006: Unhealthy for Sensitive Groups 7 of 257 days20062007: Good 142 of 266 days2007: Moderate 114 of 266 days2007: Unhealthy for Sensitive Groups 9 of 266 days2007: Unhealthy 1 of 266 days2008: Good 147 of 256 days2008: Moderate 101 of 256 days2008: Unhealthy for Sensitive Groups 8 of 256 days20082009: Good 216 of 281 days2009: Moderate 65 of 281 days2010: Good 159 of 260 days2010: Moderate 99 of 260 days2010: Unhealthy for Sensitive Groups 2 of 260 days20102011: Good 164 of 259 days2011: Moderate 90 of 259 days2011: Unhealthy for Sensitive Groups 4 of 259 days2011: Unhealthy 1 of 259 days2012: Good 218 of 276 days2012: Moderate 57 of 276 days2012: Unhealthy for Sensitive Groups 1 of 276 days20122013: Good 217 of 262 days2013: Moderate 45 of 262 days2014: Good 177 of 214 days2014: Moderate 37 of 214 days20142015: Good 185 of 209 days2015: Moderate 24 of 209 days2016: Good 171 of 193 days2016: Moderate 22 of 193 days20162017: Good 279 of 304 days2017: Moderate 25 of 304 days2018: Good 249 of 278 days2018: Moderate 28 of 278 days2018: Unhealthy for Sensitive Groups 1 of 278 days20182019: Good 205 of 237 days2019: Moderate 32 of 237 days2020: Good 290 of 296 days2020: Moderate 6 of 296 days20202021: Good 284 of 306 days2021: Moderate 22 of 306 days2022: Good 217 of 241 days2022: Moderate 23 of 241 days2022: Unhealthy for Sensitive Groups 1 of 241 days20222023: Good 272 of 305 days2023: Moderate 32 of 305 days2023: Unhealthy for Sensitive Groups 1 of 305 days2024: Good 295 of 308 days2024: Moderate 13 of 308 days20242025: Good 239 of 245 days2025: Moderate 6 of 245 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 year0501001501998: 90th percentile AQI 1151999: 90th percentile AQI 1052000: 90th percentile AQI 932001: 90th percentile AQI 872002: 90th percentile AQI 972003: 90th percentile AQI 782004: 90th percentile AQI 742005: 90th percentile AQI 902006: 90th percentile AQI 842007: 90th percentile AQI 842008: 90th percentile AQI 772009: 90th percentile AQI 582010: 90th percentile AQI 712011: 90th percentile AQI 742012: 90th percentile AQI 582013: 90th percentile AQI 552014: 90th percentile AQI 612015: 90th percentile AQI 512016: 90th percentile AQI 512017: 90th percentile AQI 502018: 90th percentile AQI 512019: 90th percentile AQI 542020: 90th percentile AQI 452021: 90th percentile AQI 492022: 90th percentile AQI 502023: 90th percentile AQI 512024: 90th percentile AQI 462025: 90th percentile AQI 471998: Median AQI 541999: Median AQI 502000: Median AQI 532001: Median AQI 482002: Median AQI 522003: Median AQI 482004: Median AQI 452005: Median AQI 502006: Median AQI 492007: Median AQI 492008: Median AQI 472009: Median AQI 412010: Median AQI 472011: Median AQI 452012: Median AQI 412013: Median AQI 382014: Median AQI 402015: Median AQI 412016: Median AQI 402017: Median AQI 352018: Median AQI 362019: Median AQI 422020: Median AQI 322021: Median AQI 342022: Median AQI 392023: Median AQI 392024: Median AQI 342025: Median AQI 35199820002002200420062008201020122014201620182020202220242025
  • 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
Ozone245100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202524523960000354771Ozone
2024308295130000344677Ozone
20233052723210003951105Ozone
20222412172310003950108Ozone
2021306284220000344997Ozone
202029629060000324558Ozone
2019237205320000425487Ozone
20182782492810003651108Ozone
2017304279250000355090Ozone
2016193171220000405197Ozone
2015209185240000415180Ozone
2014214177370000406193Ozone
20132622174500003855100Ozone
20122762185710004158143Ozone
20112591649041004574162Ozone
20102601599920004771140Ozone
2009281216650000415890Ozone
200825614710180004777129Ozone
200726614211491004984164Ozone
200625713811270004984136Ozone
2005255129107172005090173Ozone
200425314610430004574126Ozone
200325614410363004878166Ozone
2002260122115203005297174Ozone
2001264141105171004887156Ozone
2000263119123192005393182Ozone
1999249126932460050105192Ozone
1998214102762970054115179Ozone

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 North Carolina with a similar median AQI in 2025

All monitored counties in North Carolina

Source: U.S. EPA AirData, “Annual AQI by County” files for 1998–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem