EnviroNearby

Lebanon County, Pennsylvania air quality history

Daily Air Quality Index summaries from EPA monitors in Lebanon, Pennsylvania, 2011–2025.

64%
Good days in 2025
42
Median daily AQI, 2025
2
Days above 100 in 2025
365
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Lebanon, Pennsylvania on 365 days. 235 of those days (64%) were in the Good range, and the median daily AQI was 42. That median is about the same as the typical monitored county in Pennsylvania (median 40 across 38 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 208 days. Across the years with fuller monitoring, the share of Good days rose: an average of 41% in 2011–2013 versus 62% 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%2011: Good 137 of 306 days2011: Moderate 155 of 306 days2011: Unhealthy for Sensitive Groups 13 of 306 days2011: Unhealthy 1 of 306 days20112012: Good 114 of 366 days2012: Moderate 240 of 366 days2012: Unhealthy for Sensitive Groups 12 of 366 days2013: Good 169 of 365 days2013: Moderate 185 of 365 days2013: Unhealthy for Sensitive Groups 11 of 365 days20132014: Good 128 of 365 days2014: Moderate 229 of 365 days2014: Unhealthy for Sensitive Groups 8 of 365 days2015: Good 174 of 365 days2015: Moderate 179 of 365 days2015: Unhealthy for Sensitive Groups 12 of 365 days20152016: Good 95 of 366 days2016: Moderate 264 of 366 days2016: Unhealthy for Sensitive Groups 7 of 366 days2017: Good 114 of 365 days2017: Moderate 250 of 365 days2017: Unhealthy for Sensitive Groups 1 of 365 days20172018: Good 206 of 365 days2018: Moderate 157 of 365 days2018: Unhealthy for Sensitive Groups 2 of 365 days2019: Good 219 of 360 days2019: Moderate 137 of 360 days2019: Unhealthy for Sensitive Groups 4 of 360 days20192020: Good 116 of 170 days2020: Moderate 53 of 170 days2020: Unhealthy for Sensitive Groups 1 of 170 days2021: Good 197 of 365 days2021: Moderate 166 of 365 days2021: Unhealthy for Sensitive Groups 2 of 365 days20212022: Good 224 of 364 days2022: Moderate 138 of 364 days2022: Unhealthy for Sensitive Groups 2 of 364 days2023: Good 204 of 365 days2023: Moderate 151 of 365 days2023: Unhealthy for Sensitive Groups 5 of 365 days2023: Unhealthy 3 of 365 days2023: Very Unhealthy 2 of 365 days20232024: Good 242 of 366 days2024: Moderate 122 of 366 days2024: Unhealthy for Sensitive Groups 2 of 366 days2025: Good 235 of 365 days2025: Moderate 128 of 365 days2025: Unhealthy for Sensitive Groups 2 of 365 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 year0501002011: 90th percentile AQI 842012: 90th percentile AQI 872013: 90th percentile AQI 742014: 90th percentile AQI 792015: 90th percentile AQI 842016: 90th percentile AQI 712017: 90th percentile AQI 722018: 90th percentile AQI 692019: 90th percentile AQI 662020: 90th percentile AQI 602021: 90th percentile AQI 692022: 90th percentile AQI 622023: 90th percentile AQI 742024: 90th percentile AQI 642025: 90th percentile AQI 652011: Median AQI 532012: Median AQI 572013: Median AQI 522014: Median AQI 552015: Median AQI 522016: Median AQI 552017: Median AQI 562018: Median AQI 472019: Median AQI 462020: Median AQI 412021: Median AQI 492022: Median AQI 462023: Median AQI 472024: Median AQI 432025: Median AQI 4220112013201520172019202120232025
  • 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)20857%
Ozone15743%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536523512820004265108PM2.5
202436624212220004364108PM2.5
202336520415153204774265PM2.5
202236422413820004662108PM2.5
202136519716620004969117PM2.5
20201701165310004160115PM2.5
201936021913740004666142PM2.5
201836520615720004769101PM2.5
201736511425010005672127PM2.5
20163669526470005571122PM2.5
2015365174179120005284133PM2.5
201436512822980005579121PM2.5
2013365169185110005274141PM2.5
2012366114240120005787129PM2.5
2011306137155131005384151PM2.5

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 Pennsylvania with a similar median AQI in 2025

All monitored counties in Pennsylvania

Source: U.S. EPA AirData, “Annual AQI by County” files for 2011–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem