Median AQI
43
Good
Ohio · County air quality · 2025
Medina County, Ohio
Median AQI 43 (Good). 69.0% of monitored days rated Good, direct from EPA Air Quality System stations.
- 43
- Median AQI
- 69.0%
- Good-air days
- 0
- Unhealthy days
- 30%
- Cleaner than US counties
Medina County's 2025 annual median AQI is 43 (Good), with 69.0% Good days
According to the U.S. EPA Air Quality System, Medina County, Ohio posted a 2025 median AQI of 43 (Good) across 361 monitored days, with 69.0% 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
- Medina County's 69.0% Good-day share places it cleaner than 30% of US counties in 2025.
- Closest median-AQI peer
- Ashtabula County (81.2% Good, median AQI 43) is the closest nationwide median-AQI peer to Medina County.
- 2020–2025 trend
- Medina County's floor-qualifying Good-day share is worsening from 2020 to 2025 (77.8% → 69.0%).
- Median AQI
- Median AQI: 43
The verdict
According to EPA Air Quality System monitoring data, Medina County's air is good on balance, more polluted than the median US county, a median AQI of 43 with 69.0% of 361 monitored days in the Good band, driven mainly by Ozone.
- 43
- median AQI · Good
- 69.0%
- days rated Good
- Ozone
- main pollutant
- 30%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 126.
Annual release change
What changed in the 2025 EPA annual release
- Medina County's Good-day share rose from 64.5% to 69.0% between the 2024 and 2025 EPA annual releases, a change of +4.5 percentage points.
- Medina County's peak single-day AQI rose from 100 to 126 between the 2024 and 2025 EPA annual releases, a change of +26 points.
Data updated August 2026
- Good · 249 d · 69.0%
- Moderate · 110 d · 30.5%
- USG · 2 d · 0.6%
How did Medina County's air break down in 2025?
Across 361 monitored days, 249 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 126 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 361 days monitored. Median AQI: 43 (Good).
Insights: Medina County, Ohio. EPA monitors recorded a median Air Quality Index of 43 across 361 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 249 (69%) fell in the Good band (AQI 0–50), 110 (30%) registered Moderate readings, and 2 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 67, while the worst single-day peak hit 126 (USG). Residents averaged about 20.7 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (187 days), PM2.5 (174 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -8.8 points and the median AQI moved +5 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 126, 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
69.0%
249 of 361 monitored days
-6.0pp vs 75% target
Max AQI Recorded
126
USG
Health Grade
Moderate
90th-pct AQI 67
Medina County, Good days share 69.0%
National avg
Share of monitored days at AQI 0-50 (Good band).
Medina 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 361 monitored days across EPA AQI categories.
Good
249
69%
Moderate
110
30%
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 Medina County.
- Ozone · 187 days · 51.8%
- PM2.5 · 174 days · 48.2%
Health Impact Assessment
Moderate
Medina County's air quality is rated Moderate based on 69.0% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 69.0% of monitored days in 2025, with a median AQI of 43. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 187 of 361 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Medina County. Highest Good-day share: 2022 (78.5%, 284 of 362 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 280 | 80 | 0 | 0 | 38 | 93 |
| 2021 | 250 | 113 | 0 | 0 | 42 | 93 |
| 2022 | 284 | 76 | 2 | 0 | 41 | 126 |
| 2023 | 228 | 125 | 7 | 2 | 44 | 285 |
| 2024 | 236 | 130 | 0 | 0 | 44 | 100 |
| 2025 | 249 | 110 | 2 | 0 | 43 | 126 |
How does Medina County compare?
How Medina County compares
Good-day share worse than typical
Medina County 69.0%
Ashtabula County, Ohio 81.2%
Typical US county 76.0%
Median AQI worse than typical
Medina County 43
Ashtabula County, Ohio 43
Typical US county 39
Unhealthy days / yr better than typical
Medina County 0
Ashtabula County, Ohio 0
Typical US county 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Medina County (43), not geographic neighbors.
Ashtabula County, Ohio
Median AQI 43 · 81.2% Good-day share
Baltimore (City) County, Maryland
Median AQI 43 · 68.1% Good-day share
Bartholomew County, Indiana
Median AQI 43 · 72.6% Good-day share
Berks County, Pennsylvania
Median AQI 43 · 68.2% Good-day share
Bolivar County, Mississippi
Median AQI 43 · 71.9% Good-day share
Brewster County, Texas
Median AQI 43 · 74.7% Good-day share
Same primary pollutant: Ozone
Ozone 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).
Garfield County, Colorado
69.0% Good-day share · median AQI 47
Kenosha County, Wisconsin
69.2% Good-day share · median AQI 42
Lea County, New Mexico
68.8% Good-day share · median AQI 44
Washtenaw County, Michigan
69.3% Good-day share · median AQI 41
Fremont County, Wyoming
69.6% Good-day share · median AQI 47
Lincoln County, New Mexico
68.3% Good-day share · median AQI 44
Ohio counties on the map
Geographic containment only, other monitored counties in Ohio, independent of AQI or pollutant match.
What Medina County's air means for you
The air here stays in the breathable range year-round, with Ozone the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-Ozone days, the guide explains what a median of 43 means for exposure. Health guidance
- See how Medina County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Medina County with its Ohio neighbours before drawing a conclusion about the region. All of Ohio
Based on 361 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 Medina County, Ohio? ▼
Medina County has a median Air Quality Index (AQI) of 43, rated "Good." 69.0% of monitored days (249 out of 361) had good air quality in 2025.
What is the main pollutant in Medina County? ▼
The primary pollutant in Medina County is Ozone (O3), which was the main AQI driver on 187 days (52% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Medina County have? ▼
In 2025, Medina County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 126.
Is the air quality in Medina County getting better or worse? ▼
Air quality in Medina 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: 2022 at 78.5% (284 of 362 days). Lowest qualifying Good-day share: 2023 at 63.0% (228 of 363 days).
What does AQI 43 mean for health? ▼
Medina County's median AQI of 43 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Medina County compare to other counties in Ohio? ▼
Medina County has 69.0% 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 Medina County? ▼
The 90th percentile AQI for Medina County is 67, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 126 (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 Medina 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.