Median AQI
40
Good
Kentucky · County air quality · 2025
Fayette County, Kentucky
Median AQI 40 (Good). 75.3% of monitored days rated Good, direct from EPA Air Quality System stations.
- 40
- Median AQI
- 75.3%
- Good-air days
- 0
- Unhealthy days
- 41%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Fayette County's air is good on balance, more polluted than the median US county, a median AQI of 40 with 75.3% of 186 monitored days in the Good band, driven mainly by PM2.5.
- 40
- median AQI · Good
- 75.3%
- days rated Good
- PM2.5
- main pollutant
- 41%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 76.
Data updated July 2026
- Good · 140 d · 75.3%
- Moderate · 46 d · 24.7%
How did Fayette County's air break down in 2025?
Across 186 monitored days, 140 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 76 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 186 days monitored. Median AQI: 40 (Good).
Insights: Fayette County, Kentucky. EPA monitors recorded a median Air Quality Index of 40 across 186 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 140 (75%) fell in the Good band (AQI 0–50), 46 (25%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 56, while the worst single-day peak hit 76 (Moderate). Residents averaged about 22.6 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (99 days), Ozone (78 days), PM10 (6 days), NO2 (3 days). Across the 2020–2025 trend window, good days shifted by -118 and the median AQI moved -2 points, placing the multi-year trajectory at improving. The worst single reading over the 2020–2025 window was AQI 76, moderate but never Unhealthy. Nearby counties show comparable readings: Bell (63.5% good, AQI 43); Boone (95.1% good, AQI 38); Boyd (82.8% good, AQI 39); Bullitt (92.7% good, AQI 39); Campbell (78.5% good, AQI 39); Carter (89.8% good, AQI 36).
Air Quality Summary
Good Days
75.3%
140 of 186 monitored days
0.3pp vs 75% target
Max AQI Recorded
76
Moderate
Health Grade
Good
90th-pct AQI 56
Fayette County, Good days share 75.3%
National avg
Share of monitored days at AQI 0-50 (Good band).
Fayette 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 186 monitored days across EPA AQI categories.
Good
140
75%
Moderate
46
25%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Fayette County.
- PM2.5 · 99 days · 53.2%
- Ozone · 78 days · 41.9%
- PM10 · 6 days · 3.2%
- NO₂ · 3 days · 1.6%
Health Impact Assessment
Good
Fayette County's air quality is rated Good based on 75.3% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 75.3% of monitored days in 2025, with a median AQI of 40. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 99 of 186 monitored days.
5-Year Air Quality Trend
Air quality is improving in Fayette County. Best year: 2024 (266 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 258 | 108 | 0 | 0 | 42 | 86 |
| 2021 | 214 | 148 | 1 | 0 | 47 | 108 |
| 2022 | 235 | 129 | 1 | 0 | 44 | 106 |
| 2023 | 232 | 131 | 1 | 1 | 45 | 167 |
| 2024 | 266 | 70 | 0 | 0 | 41 | 77 |
| 2025 | 140 | 46 | 0 | 0 | 40 | 76 |
How does Fayette County compare?
How Fayette County compares
Good-day share worse than US avg
Fayette County 75.3%
Bell County, Kentucky 63.5%
US average 76.5%
Median AQI worse than US avg
Fayette County 40
Bell County, Kentucky 43
US average 38
Unhealthy days / yr about average
Fayette County 0
Bell County, Kentucky 0
US average 0
Other Counties in Kentucky
Air quality comparison for nearby counties in Kentucky.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Fayette County.
Amador County, California
AQI 40 · 84.8% good
Anne Arundel County, Maryland
AQI 40 · 87.2% good
Arlington County, Virginia
AQI 40 · 84.8% good
Bergen County, New Jersey
AQI 40 · 71.1% good
Berkeley County, West Virginia
AQI 40 · 81.1% good
Billings County, North Dakota
AQI 40 · 80.3% good
What Fayette 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 40 means for exposure. Health guidance
- See how Fayette County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Fayette County with its Kentucky neighbours before drawing a conclusion about the region. All of Kentucky
Based on 186 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
More Air Quality Data
Air Quality Guides
Frequently Asked Questions
What is the air quality in Fayette County, Kentucky? ▼
Fayette County has a median Air Quality Index (AQI) of 40, rated "Good." 75.3% of monitored days (140 out of 186) had good air quality in 2025.
What is the main pollutant in Fayette County? ▼
The primary pollutant in Fayette County is Fine Particles (PM2.5), which was the main AQI driver on 99 days (53% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Fayette County have? ▼
In 2025, Fayette County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 76.
Is the air quality in Fayette County getting better or worse? ▼
Air quality in Fayette County is improving based on 5-year trends (2020-2025). Best year: 2024 with 266 good days. Worst year: 2025 with 140 good days.
What does AQI 40 mean for health? ▼
Fayette County's median AQI of 40 falls in the "Good" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Fayette County compare to other counties in Kentucky? ▼
Fayette County has 75.3% good air days. Nearby counties in Kentucky: Bell (63.5% good), Boone (95.1% good), Boyd (82.8% good), Bullitt (92.7% good), Campbell (78.5% good), Carter (89.8% good).
What is the 90th percentile AQI in Fayette County? ▼
The 90th percentile AQI for Fayette County is 56, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 76 (Moderate).
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.
Every figure on PlainAir 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.