Median AQI
43
Good
Kentucky · County air quality · 2025
Hancock County, Kentucky
Median AQI 43 (Good). 82.6% of monitored days rated Good, direct from EPA Air Quality System stations.
- 43
- Median AQI
- 82.6%
- Good-air days
- 0
- Unhealthy days
- 63%
- Cleaner than US counties
Hancock County's 2025 annual median AQI is 43 (Good), with 82.6% Good days
According to the U.S. EPA Air Quality System, Hancock County, Kentucky posted a 2025 median AQI of 43 (Good) across 242 monitored days, with 82.6% 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
- Hancock County's 82.6% Good-day share places it cleaner than 63% 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 Hancock County.
- 2020–2025 trend
- Hancock County's floor-qualifying Good-day share is worsening from 2020 to 2025 (95.1% → 82.6%).
- Median AQI
- Median AQI: 43
The verdict
According to EPA Air Quality System monitoring data, Hancock County's air is good on balance, cleaner than the median US county, a median AQI of 43 with 82.6% of 242 monitored days in the Good band, driven mainly by Ozone.
- 43
- median AQI · Good
- 82.6%
- days rated Good
- Ozone
- main pollutant
- 63%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 97.
Annual release change
What changed in the 2025 EPA annual release
- Hancock County's Good-day share fell from 87.3% to 82.6% between the 2024 and 2025 EPA annual releases, a change of -4.7 percentage points.
Data updated August 2026
- Good · 200 d · 82.6%
- Moderate · 42 d · 17.4%
How did Hancock County's air break down in 2025?
Across 242 monitored days, 200 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 97 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 242 days monitored. Median AQI: 43 (Good).
Insights: Hancock County, Kentucky. EPA monitors recorded a median Air Quality Index of 43 across 242 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 200 (83%) fell in the Good band (AQI 0–50), 42 (17%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 58, while the worst single-day peak hit 97 (Moderate). Residents averaged about 24.8 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (242 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -12.5 points and the median AQI moved +6 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 97, moderate but never Unhealthy. Nearby counties show comparable readings: Bell (67.0% good, AQI 42); Boone (87.6% good, AQI 38); Boyd (80.0% good, AQI 39); Bullitt (88.4% good, AQI 39); Campbell (75.6% good, AQI 39); Carter (89.0% good, AQI 36).
Air Quality Summary
Good Days
82.6%
200 of 242 monitored days
7.6pp vs 75% target
Max AQI Recorded
97
Moderate
Health Grade
Good
90th-pct AQI 58
Hancock County, Good days share 82.6%
National avg
Share of monitored days at AQI 0-50 (Good band).
Hancock 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 242 monitored days across EPA AQI categories.
Good
200
83%
Moderate
42
17%
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 Hancock County.
- Ozone · 242 days · 100.0%
Health Impact Assessment
Good
Hancock County's air quality is rated Good based on 82.6% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 82.6% 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 242 of 242 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Hancock County. Highest Good-day share: 2020 (95.1%, 233 of 245 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 233 | 12 | 0 | 0 | 37 | 97 |
| 2021 | 220 | 21 | 0 | 0 | 38 | 90 |
| 2022 | 219 | 23 | 1 | 0 | 40 | 108 |
| 2023 | 201 | 38 | 6 | 0 | 42 | 140 |
| 2024 | 200 | 29 | 0 | 0 | 44 | 100 |
| 2025 | 200 | 42 | 0 | 0 | 43 | 97 |
How does Hancock County compare?
How Hancock County compares
Good-day share better than typical
Hancock County 82.6%
Ashtabula County, Ohio 81.2%
Typical US county 76.0%
Median AQI worse than typical
Hancock County 43
Ashtabula County, Ohio 43
Typical US county 39
Unhealthy days / yr better than typical
Hancock 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 Hancock 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).
Billings County, North Dakota
82.7% Good-day share · median AQI 38
Randall County, Texas
82.8% Good-day share · median AQI 41
Westchester County, New York
82.5% Good-day share · median AQI 38
Horry County, South Carolina
82.5% Good-day share · median AQI 39
Geauga County, Ohio
82.9% Good-day share · median AQI 42
Wood County, West Virginia
82.9% Good-day share · median AQI 39
Kentucky counties on the map
Geographic containment only, other monitored counties in Kentucky, independent of AQI or pollutant match.
What Hancock 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 Hancock County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Hancock County with its Kentucky neighbours before drawing a conclusion about the region. All of Kentucky
Based on 242 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 Hancock County, Kentucky? ▼
Hancock County has a median Air Quality Index (AQI) of 43, rated "Good." 82.6% of monitored days (200 out of 242) had good air quality in 2025.
What is the main pollutant in Hancock County? ▼
The primary pollutant in Hancock County is Ozone (O3), which was the main AQI driver on 242 days (100% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Hancock County have? ▼
In 2025, Hancock County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 97.
Is the air quality in Hancock County getting better or worse? ▼
Air quality in Hancock 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 95.1% (233 of 245 days). Lowest qualifying Good-day share: 2023 at 82.0% (201 of 245 days).
What does AQI 43 mean for health? ▼
Hancock 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 Hancock County compare to other counties in Kentucky? ▼
Hancock County has 82.6% good air days. Nearby counties in Kentucky: Bell (67.0% good), Boone (87.6% good), Boyd (80.0% good), Bullitt (88.4% good), Campbell (75.6% good), Carter (89.0% good).
What is the 90th percentile AQI in Hancock County? ▼
The 90th percentile AQI for Hancock County is 58, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 97 (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. Spotted a figure that looks wrong? Report a correction.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Hancock County, Kentucky · 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.