Pennsylvania · County air quality · 2025

Lebanon County, Pennsylvania

Median AQI 42 (Good). 64.4% of monitored days rated Good, direct from EPA Air Quality System stations.

42
Median AQI
64.4%
Good-air days
0
Unhealthy days
22%
Cleaner than US counties

Lebanon County's 2025 annual median AQI is 42 (Good), with 64.4% Good days

According to the U.S. EPA Air Quality System, Lebanon County, Pennsylvania posted a 2025 median AQI of 42 (Good) across 365 monitored days, with 64.4% rated Good and 0 unhealthy or worse. This is an annual comparison, not today's advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US
Lebanon County's 64.4% Good-day share places it cleaner than 22% of US counties in 2025.
Closest median-AQI peer
Ada County (74.0% Good, median AQI 42) is the closest nationwide median-AQI peer to Lebanon County.
2020–2025 trend
Lebanon County's floor-qualifying Good-day share is worsening from 2020 to 2025 (68.2% → 64.4%).
Median AQI
Median AQI: 42

According to the 2025 EPA AQS county release on PlainAirData, Lebanon County, Pennsylvania ranks #581 of 951 by median AQI (42) and #742 by good-day share (64.4%). Ponce County, Puerto Rico is #1 of 951 by median AQI (3, 91.4% Good days) at good-day-share #159 ≠ largest of 7 at 100.0% Good days #1 by good-day share (100.0%, median AQI 9) at median-AQI #7.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Lebanon County's Good-day share fell from 66.1% to 64.4% between the 2024 and 2025 EPA annual releases, a change of -1.7 percentage points.

Compared against 366 monitored days in 2024 and 365 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Data updated August 2026

Lebanon County AQI category distribution Stacked-segment bar showing the share of monitored days that fell in each EPA AQI category, Good, Moderate, USG, Unhealthy, Very Unhealthy, Hazardous, with median AQI marker. AQI category distribution 365 monitored days G M Median AQI 42 0 50 100 150 200 300 500 Lebanon County
  • Good · 235 d · 64.4%
  • Moderate · 128 d · 35.1%
  • USG · 2 d · 0.5%

How did Lebanon County's air break down in 2025?

Across 365 monitored days, 235 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 108 (USG).

EPA AQS →
Lebanon County, Good days share 64.4%
National avg

Share of monitored days at AQI 0-50 (Good band).

Lebanon County, Unhealthy-or-worse share 0.0%
National avg

Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).

Where Lebanon County sits nationally

COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Lebanon County's Good-day share is 64.4% - cleaner than 22% of that comparison set.

Lebanon County Good-day share vs. every US county

Share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release

64.4% 22nd percentile higher than 22% of 951 US counties

0.0%–5.0%: 0 US counties (0%). Below this entry. 5.0%–10.0%: 1 US counties (0%). Below this entry. 10.0%–15.0%: 4 US counties (0%). Below this entry. 15.0%–20.0%: 4 US counties (0%). Below this entry. 20.0%–25.0%: 1 US counties (0%). Below this entry. 25.0%–30.0%: 5 US counties (1%). Below this entry. 30.0%–35.0%: 9 US counties (1%). Below this entry. 35.0%–40.0%: 4 US counties (0%). Below this entry. 40.0%–45.0%: 16 US counties (2%). Below this entry. 45.0%–50.0%: 16 US counties (2%). Below this entry. 50.0%–55.0%: 32 US counties (3%). Below this entry. 55.0%–60.0%: 50 US counties (5%). Below this entry. 60.0%–65.0%: 77 US counties (8%). This entry sits in this band. 65.0%–70.0%: 93 US counties (10%). Above this entry. 70.0%–75.0%: 109 US counties (11%). Above this entry. 75.0%–80.0%: 114 US counties (12%). Above this entry. 80.0%–85.0%: 123 US counties (13%). Above this entry. 85.0%–90.0%: 99 US counties (10%). Above this entry. 90.0%–95.0%: 117 US counties (12%). Above this entry. 95.0%–100.0%: 70 US counties (7%). Above this entry. 100.0%–105.0%: 7 US counties (1%). Above this entry. This county 0.0% 100% every floor-qualified US county, bucketed by value

Each bar is a band; taller bars hold more US counties. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source U.S. Environmental Protection Agency, Air Quality System (AQS) · 2025

Pollutant Breakdown

Days where each pollutant was the primary driver of AQI readings in Lebanon County.

Lebanon County, Pennsylvania criteria pollutant distribution Stratified-band visualization showing the share of monitored days each criteria pollutant (PM2.5, PM10, O3, NO2, CO) was the primary AQI driver. PM2.5 · 57.0% Ozone · 43.0% 0% 25% 50% 75% 100% Lebanon County, Pennsylvania · 365 monitored days Criteria pollutant column
  • PM2.5 · 208 days · 57.0%
  • Ozone · 157 days · 43.0%

2024 daily-monitor rhythm in Lebanon County

Month-by-month median AQI from EPA day-level county monitors (366 reported days in 2024). Jul posted the highest typical readings (median AQI 50, peak 87); Nov was cleanest at median 38. Summer months (Jun–Aug) averaged median AQI 49 vs 45 in Dec–Feb.

0 10 20 30 40 50 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 42 49 38 44 42 49 50 47 40 41 38 44
Lebanon County median daily AQI by calendar month (2024, EPA daily county file)

Five-year seasonal record

EPA day-level county files · 2020–2024

1,630 daily readings show a recurring local pattern: Jul has the highest matched-month median AQI (51), while Sep is lowest (36). Each cell is that month’s median daily AQI, not a current-air forecast.

JanFebMarAprMayJunJulAugSepOctNovDec
2020 515238--29454624313946
2021 375142524246555141465061
2022 524647394248534337424751
2023 535344504771544139374554
2024 424938444249504740413844

Lower AQI is better. The colors summarize EPA AQI bands; gaps mean the county had no day-level record for that month.

Health Impact Assessment

Moderate

Lebanon County's air quality is rated Moderate based on 64.4% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 64.4% of monitored days in 2025, with a median AQI of 42. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.

The dominant pollutant is PM2.5, driving AQI on 208 of 365 monitored days.

5-Year Air Quality Trend

Air quality is worsening in Lebanon County. Highest Good-day share: 2020 (68.2%, 116 of 170 monitored days).

Year Good Moderate USG Unhealthy Median AQI
2020 116 53 1 0 41
2021 197 166 2 0 49
2022 224 138 2 0 46
2023 204 151 5 3 47
2024 242 122 2 0 43
2025 235 128 2 0 42

How does Lebanon County compare?

How Lebanon County compares

Good-day share worse than typical
Lebanon County 64.4%
Ada County, Idaho 74.0%
Typical US county 76.0%
Median AQI worse than typical
Lebanon County 42
Ada County, Idaho 42
Typical US county 39
Unhealthy days / yr better than typical
Lebanon County 0
Ada County, Idaho 0
Typical US county 1

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.

Informational only, not professional advice. Data from EPA AQS. See our disclaimer. Spotted a figure that looks wrong? Report a correction.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Lebanon County, Pennsylvania · 2020–2025

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Download this county's annual AQI row as CSV , with the same EPA fields and denominator shown on this page.

Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.