EnviroNearby

Susquehanna County, Pennsylvania air quality history

Daily Air Quality Index summaries from EPA monitors in Susquehanna, Pennsylvania, 2018–2025.

88%
Good days in 2025
22
Median daily AQI, 2025
2
Days above 100 in 2025
311
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Susquehanna, Pennsylvania on 311 days. 275 of those days (88%) were in the Good range, and the median daily AQI was 22. That median is lower than the typical monitored county in Pennsylvania (median 40 across 38 counties), and lower than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 311 days. Across the years with fuller monitoring, the share of Good days rose: an average of 81% in 2019–2021 versus 87% in 2023–2025.

Years with fewer than 120 monitored days (2018) 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%2018: Good 71 of 88 days2018: Moderate 17 of 88 days20182019: Good 292 of 352 days2019: Moderate 60 of 352 days20192020: Good 311 of 365 days2020: Moderate 54 of 365 days20202021: Good 252 of 334 days2021: Moderate 80 of 334 days2021: Unhealthy for Sensitive Groups 2 of 334 days20212022: Good 219 of 279 days2022: Moderate 60 of 279 days20222023: Good 126 of 152 days2023: Moderate 26 of 152 days20232024: Good 321 of 358 days2024: Moderate 37 of 358 days20242025: Good 275 of 311 days2025: Moderate 34 of 311 days2025: Unhealthy for Sensitive Groups 2 of 311 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 year0501002018: 90th percentile AQI 552019: 90th percentile AQI 552020: 90th percentile AQI 522021: 90th percentile AQI 572022: 90th percentile AQI 542023: 90th percentile AQI 532024: 90th percentile AQI 512025: 90th percentile AQI 512018: Median AQI 322019: Median AQI 322020: Median AQI 312021: Median AQI 352022: Median AQI 332023: Median AQI 282024: Median AQI 252025: Median AQI 2220182019202020212022202320242025
  • 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)311100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253112753420002251107PM2.5
2024358321370000255164PM2.5
2023152126260000285364PM2.5
2022279219600000335467PM2.5
20213342528020003557133PM2.5
2020365311540000315274PM2.5
2019352292600000325579PM2.5
20188871170000325567PM2.5

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 2018–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem