Pennsylvania · County air quality · 2025

Elk County, Pennsylvania

Median AQI 36 (Good). 95.3% of monitored days rated Good, direct from EPA Air Quality System stations.

36
Median AQI
95.3%
Good-air days
0
Unhealthy days
92%
Cleaner than US counties

Elk County's 2025 annual median AQI is 36 (Good), with 95.3% Good days

According to the U.S. EPA Air Quality System, Elk County, Pennsylvania posted a 2025 median AQI of 36 (Good) across 361 monitored days, with 95.3% 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
Elk County's 95.3% Good-day share places it cleaner than 92% 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 Elk County.
2020–2025 trend
Elk County's floor-qualifying Good-day share is worsening from 2020 to 2025 (99.4% → 95.3%).
Median AQI
Median AQI: 36

According to the 2025 EPA AQS county release on PlainAirData, Elk County, Pennsylvania ranks #233 of 951 by median AQI (36) and #72 by good-day share (95.3%). 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
  • Elk County's peak single-day AQI rose from 67 to 84 between the 2024 and 2025 EPA annual releases, a change of +17 points.

Compared against 358 monitored days in 2024 and 361 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

Elk 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 361 monitored days G Median AQI 36 0 50 100 150 200 300 500 Elk County
  • Good · 344 d · 95.3%
  • Moderate · 17 d · 4.7%

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

Across 361 monitored days, 344 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 84 (Moderate).

EPA AQS →
Elk County, Good days share 95.3%
National avg

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

Elk 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 Elk County sits nationally

COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Elk County's Good-day share is 95.3% - cleaner than 92% of that comparison set.

Elk County Good-day share vs. every US county

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

95.3% Cleaner than 92% higher than 92% 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%). Below this entry. 90.0%–95.0%: 117 US counties (12%). Below this entry. 95.0%–100.0%: 70 US counties (7%). This entry sits in this band. 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 Elk County.

Elk 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 · 100.0% 0% 25% 50% 75% 100% Elk County, Pennsylvania · 361 monitored days Criteria pollutant column
  • Ozone · 361 days · 100.0%

2024 daily-monitor rhythm in Elk County

Month-by-month median AQI from EPA day-level county monitors (358 reported days in 2024). Jul posted the highest typical readings (median AQI 41, peak 54); Nov was cleanest at median 27. Summer months (Jun–Aug) averaged median AQI 37 vs 30 in Dec–Feb.

0 10 20 30 40 50 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 29 34 37 40 40 38 41 31 35 34 27 28
Elk County median daily AQI by calendar month (2024, EPA daily county file)

Five-year seasonal record

EPA day-level county files · 2020–2024

1,800 daily readings show a recurring local pattern: Apr has the highest matched-month median AQI (43), while Dec is lowest (28). Each cell is that month’s median daily AQI, not a current-air forecast.

JanFebMarAprMayJunJulAugSepOctNovDec
2020 313437434036363529293128
2021 313742434038343431303030
2022 323740424041393330343128
2023 283641474442423331293227
2024 293437404038413135342728

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

Excellent

Elk County's air quality is rated Excellent based on 95.3% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 95.3% 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 361 of 361 monitored days.

5-Year Air Quality Trend

Air quality is worsening in Elk County. Highest Good-day share: 2020 (99.4%, 356 of 358 monitored days).

Year Good Moderate USG Unhealthy Median AQI
2020 356 2 0 0 34
2021 340 18 0 0 34
2022 353 9 1 0 35
2023 343 20 0 0 35
2024 343 15 0 0 34
2025 344 17 0 0 36

How does Elk County compare?

How Elk County compares

Good-day share better than typical
Elk County 95.3%
Ashland County, Wisconsin 81.6%
Typical US county 76.0%
Median AQI better than typical
Elk County 36
Ashland County, Wisconsin 36
Typical US county 39
Unhealthy days / yr better than typical
Elk 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 Elk 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.