Pennsylvania · County air quality · 2025

Bucks County, Pennsylvania

Median AQI 36 (Good). 86.2% of monitored days rated Good, direct from EPA Air Quality System stations.

36
Median AQI
86.2%
Good-air days
0
Unhealthy days
72%
Cleaner than US counties

Bucks County's 2025 annual median AQI is 36 (Good), with 86.2% Good days

According to the U.S. EPA Air Quality System, Bucks County, Pennsylvania posted a 2025 median AQI of 36 (Good) across 362 monitored days, with 86.2% 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
Bucks County's 86.2% Good-day share places it cleaner than 72% of US counties in 2025.
Closest median-AQI peer
Ashland County (81.6% Good, median AQI 36) is the closest nationwide median-AQI peer to Bucks County.
2020–2025 trend
Bucks County's floor-qualifying Good-day share is worsening from 2020 to 2025 (94.3% → 86.2%).
Median AQI
Median AQI: 36

According to the 2025 EPA AQS county release on PlainAirData, Bucks County, Pennsylvania ranks #233 of 951 by median AQI (36) and #262 by good-day share (86.2%). 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
  • Bucks County's Good-day share rose from 82.3% to 86.2% between the 2024 and 2025 EPA annual releases, a change of +3.9 percentage points.
  • Bucks County's peak single-day AQI fell from 150 to 136 between the 2024 and 2025 EPA annual releases, a change of -14 points.

Compared against 356 monitored days in 2024 and 362 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

Bucks 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 362 monitored days G M Median AQI 36 0 50 100 150 200 300 500 Bucks County
  • Good · 312 d · 86.2%
  • Moderate · 46 d · 12.7%
  • USG · 4 d · 1.1%

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

Across 362 monitored days, 312 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 136 (USG).

EPA AQS →
Bucks County, Good days share 86.2%
National avg

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

Bucks 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 Bucks County sits nationally

COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Bucks County's Good-day share is 86.2% - cleaner than 72% of that comparison set.

Bucks County Good-day share vs. every US county

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

86.2% Cleaner than 72% higher than 72% 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%). Below this entry. 65.0%–70.0%: 93 US counties (10%). Below this entry. 70.0%–75.0%: 109 US counties (11%). Below this entry. 75.0%–80.0%: 114 US counties (12%). Below this entry. 80.0%–85.0%: 123 US counties (13%). Below this entry. 85.0%–90.0%: 99 US counties (10%). This entry sits in this band. 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 Bucks County.

Bucks 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. Ozone · 91.7% 0% 25% 50% 75% 100% Bucks County, Pennsylvania · 362 monitored days Criteria pollutant column
  • Ozone · 332 days · 91.7%
  • NO₂ · 30 days · 8.3%

2024 daily-monitor rhythm in Bucks County

Month-by-month median AQI from EPA day-level county monitors (356 reported days in 2024). Jun posted the highest typical readings (median AQI 55, peak 150); Jan was cleanest at median 25. Summer months (Jun–Aug) averaged median AQI 50 vs 28 in Dec–Feb.

0 10 20 30 40 50 60 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 25 31 37 42 43 55 54 41 37 38 30 27
Bucks County median daily AQI by calendar month (2024, EPA daily county file)

Five-year seasonal record

EPA day-level county files · 2020–2024

1,523 daily readings show a recurring local pattern: Jul has the highest matched-month median AQI (50), while Dec is lowest (24). Each cell is that month’s median daily AQI, not a current-air forecast.

JanFebMarAprMayJunJulAugSepOctNovDec
2020 273236413742454130262722
2021 24323839444446443431--
2022 --3741414454443629--
2023 --35444647514138312924
2024 253137424355544137383027

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

Good

Bucks County's air quality is rated Good based on 86.2% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 86.2% of monitored days in 2025, with a median AQI of 36. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.

The dominant pollutant is Ozone, driving AQI on 332 of 362 monitored days.

5-Year Air Quality Trend

Air quality is worsening in Bucks County. Highest Good-day share: 2020 (94.3%, 331 of 351 monitored days).

Year Good Moderate USG Unhealthy Median AQI
2020 331 16 4 0 33
2021 239 34 10 0 37
2022 196 39 2 0 41
2023 241 50 4 1 39
2024 293 53 10 0 36
2025 312 46 4 0 36

How does Bucks County compare?

How Bucks County compares

Good-day share better than typical
Bucks County 86.2%
Ashland County, Wisconsin 81.6%
Typical US county 76.0%
Median AQI better than typical
Bucks County 36
Ashland County, Wisconsin 36
Typical US county 39
Unhealthy days / yr better than typical
Bucks County 0
Ashland County, Wisconsin 8
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 Bucks 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.