Median AQI
44
Good
Ohio · County air quality · 2025
Mahoning County, Ohio
Median AQI 44 (Good). 63.4% of monitored days rated Good, direct from EPA Air Quality System stations.
- 44
- Median AQI
- 63.4%
- Good-air days
- 0
- Unhealthy days
- 20%
- Cleaner than US counties
Mahoning County's 2025 annual median AQI is 44 (Good), with 63.4% Good days
According to the U.S. EPA Air Quality System, Mahoning County, Ohio posted a 2025 median AQI of 44 (Good) across 363 monitored days, with 63.4% 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
- Mahoning County's 63.4% Good-day share places it cleaner than 20% of US counties in 2025.
- Closest median-AQI peer
- Allegan County (63.9% Good, median AQI 44) is the closest nationwide median-AQI peer to Mahoning County.
- 2020–2025 trend
- Mahoning County's floor-qualifying Good-day share is worsening from 2020 to 2025 (68.8% → 63.4%).
- Median AQI
- Median AQI: 44
The verdict
According to EPA Air Quality System monitoring data, Mahoning County's air is good on balance, among the more polluted 10% of US counties, a median AQI of 44 with 63.4% of 363 monitored days in the Good band, driven mainly by PM2.5.
- 44
- median AQI · Good
- 63.4%
- days rated Good
- PM2.5
- main pollutant
- 20%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 122.
Annual release change
What changed in the 2025 EPA annual release
- Mahoning County's peak single-day AQI rose from 93 to 122 between the 2024 and 2025 EPA annual releases, a change of +29 points.
- Mahoning County's Good-day share fell from 66.2% to 63.4% between the 2024 and 2025 EPA annual releases, a change of -2.8 percentage points.
Data updated August 2026
- Good · 230 d · 63.4%
- Moderate · 131 d · 36.1%
- USG · 2 d · 0.6%
How did Mahoning County's air break down in 2025?
Across 363 monitored days, 230 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 122 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 363 days monitored. Median AQI: 44 (Good).
Insights: Mahoning County, Ohio. EPA monitors recorded a median Air Quality Index of 44 across 363 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 230 (63%) fell in the Good band (AQI 0–50), 131 (36%) registered Moderate readings, and 2 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 65, while the worst single-day peak hit 122 (USG). Residents averaged about 19.0 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (215 days), Ozone (148 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -5.4 points and the median AQI moved +1 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 122, usg but never Unhealthy. Nearby counties show comparable readings: Allen (67.0% good, AQI 42); Ashtabula (81.2% good, AQI 43); Athens (83.4% good, AQI 31); Belmont (63.0% good, AQI 42); Butler (33.1% good, AQI 55); Clark (61.4% good, AQI 45).
Air Quality Summary
Good Days
63.4%
230 of 363 monitored days
-11.6pp vs 75% target
Max AQI Recorded
122
USG
Health Grade
Moderate
90th-pct AQI 65
Mahoning County, Good days share 63.4%
National avg
Share of monitored days at AQI 0-50 (Good band).
Mahoning 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).
AQI Day Breakdown (2025)
Distribution of 363 monitored days across EPA AQI categories.
Good
230
63%
Moderate
131
36%
USG
2
1%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Mahoning County.
- PM2.5 · 215 days · 59.2%
- Ozone · 148 days · 40.8%
Health Impact Assessment
Moderate
Mahoning County's air quality is rated Moderate based on 63.4% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 63.4% of monitored days in 2025, with a median AQI of 44. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 215 of 363 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Mahoning County. Highest Good-day share: 2020 (68.8%, 251 of 365 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 251 | 113 | 1 | 0 | 43 | 142 |
| 2021 | 205 | 159 | 1 | 0 | 47 | 110 |
| 2022 | 214 | 132 | 3 | 0 | 46 | 129 |
| 2023 | 187 | 172 | 3 | 2 | 49 | 226 |
| 2024 | 239 | 122 | 0 | 0 | 44 | 93 |
| 2025 | 230 | 131 | 2 | 0 | 44 | 122 |
How does Mahoning County compare?
How Mahoning County compares
Good-day share worse than US avg
Mahoning County 63.4%
Allegan County, Michigan 63.9%
US average 76.0%
Median AQI worse than US avg
Mahoning County 44
Allegan County, Michigan 44
US average 39
Unhealthy days / yr better than US avg
Mahoning County 0
Allegan County, Michigan 2
US average 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Mahoning County (44), not geographic neighbors.
Allegan County, Michigan
Median AQI 44 · 63.9% Good-day share
Allen County, Indiana
Median AQI 44 · 60.0% Good-day share
Baker County, Florida
Median AQI 44 · 69.5% Good-day share
Bay County, Florida
Median AQI 44 · 66.4% Good-day share
Blount County, Tennessee
Median AQI 44 · 71.5% Good-day share
Cache County, Utah
Median AQI 44 · 66.0% Good-day share
Same primary pollutant: PM2.5
PM2.5 led the AQI on the most monitored days here. These peers share that driver and the closest Good-day share (a second relationship type beyond median-AQI neighbors).
Benewah County, Idaho
63.4% Good-day share · median AQI 41
Grant County, Oregon
63.2% Good-day share · median AQI 37
Forsyth County, North Carolina
63.6% Good-day share · median AQI 45
Queens County, New York
63.6% Good-day share · median AQI 44
Summit County, Ohio
63.6% Good-day share · median AQI 44
Knox County, Tennessee
63.0% Good-day share · median AQI 46
Ohio counties on the map
Geographic containment only, other monitored counties in Ohio, independent of AQI or pollutant match.
What Mahoning County's air means for you
The air here stays in the breathable range year-round, with PM2.5 the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 44 means for exposure. Health guidance
- See how Mahoning County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Mahoning County with its Ohio neighbours before drawing a conclusion about the region. All of Ohio
Based on 363 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
Keep exploring the annual AQI record
Air-quality reading list
Frequently Asked Questions
What is the air quality in Mahoning County, Ohio? ▼
Mahoning County has a median Air Quality Index (AQI) of 44, rated "Good." 63.4% of monitored days (230 out of 363) had good air quality in 2025.
What is the main pollutant in Mahoning County? ▼
The primary pollutant in Mahoning County is Fine Particles (PM2.5), which was the main AQI driver on 215 days (59% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Mahoning County have? ▼
In 2025, Mahoning County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 122.
Is the air quality in Mahoning County getting better or worse? ▼
Air quality in Mahoning County is worsening across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2020 at 68.8% (251 of 365 days). Lowest qualifying Good-day share: 2023 at 51.4% (187 of 365 days).
What does AQI 44 mean for health? ▼
Mahoning County's median AQI of 44 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Mahoning County compare to other counties in Ohio? ▼
Mahoning County has 63.4% good air days. Nearby counties in Ohio: Allen (67.0% good), Ashtabula (81.2% good), Athens (83.4% good), Belmont (63.0% good), Butler (33.1% good), Clark (61.4% good).
What is the 90th percentile AQI in Mahoning County? ▼
The 90th percentile AQI for Mahoning County is 65, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 122 (USG).
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 Mahoning County, Ohio · 2020–2025
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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.