Median AQI
41
Good
Kentucky · County air quality · 2025
Jessamine County, Kentucky
Median AQI 41 (Good). 78.5% of monitored days rated Good, direct from EPA Air Quality System stations.
- 41
- Median AQI
- 78.5%
- Good-air days
- 0
- Unhealthy days
- 52%
- Cleaner than US counties
Jessamine County's 2025 annual median AQI is 41 (Good), with 78.5% Good days
According to the U.S. EPA Air Quality System, Jessamine County, Kentucky posted a 2025 median AQI of 41 (Good) across 363 monitored days, with 78.5% 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
- Jessamine County's 78.5% Good-day share places it cleaner than 52% of US counties in 2025.
- Closest median-AQI peer
- Armstrong County (70.5% Good, median AQI 41) is the closest nationwide median-AQI peer to Jessamine County.
- 2020–2025 trend
- Jessamine County's floor-qualifying Good-day share is worsening from 2020 to 2025 (95.5% → 78.5%).
- Median AQI
- Median AQI: 41
The verdict
According to EPA Air Quality System monitoring data, Jessamine County's air is good on balance, cleaner than the median US county, a median AQI of 41 with 78.5% of 363 monitored days in the Good band, driven mainly by Ozone.
- 41
- median AQI · Good
- 78.5%
- days rated Good
- Ozone
- main pollutant
- 52%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 100.
Annual release change
What changed in the 2025 EPA annual release
- Jessamine County's Good-day share fell from 81.6% to 78.5% between the 2024 and 2025 EPA annual releases, a change of -3.1 percentage points.
Data updated August 2026
- Good · 285 d · 78.5%
- Moderate · 78 d · 21.5%
How did Jessamine County's air break down in 2025?
Across 363 monitored days, 285 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 100 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 363 days monitored. Median AQI: 41 (Good).
Insights: Jessamine County, Kentucky. EPA monitors recorded a median Air Quality Index of 41 across 363 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 285 (79%) fell in the Good band (AQI 0–50), 78 (21%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 57, while the worst single-day peak hit 100 (Moderate). Residents averaged about 23.6 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (185 days), PM2.5 (178 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -17.0 points (measured against 243 monitored days in 2020 and 363 in 2025, so raw day counts are not comparable) and the median AQI moved +4 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 100, 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
78.5%
285 of 363 monitored days
3.5pp vs 75% target
Max AQI Recorded
100
Moderate
Health Grade
Good
90th-pct AQI 57
Jessamine County, Good days share 78.5%
National avg
Share of monitored days at AQI 0-50 (Good band).
Jessamine 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
285
79%
Moderate
78
21%
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 Jessamine County.
- Ozone · 185 days · 51.0%
- PM2.5 · 178 days · 49.0%
Health Impact Assessment
Good
Jessamine County's air quality is rated Good based on 78.5% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 78.5% of monitored days in 2025, with a median AQI of 41. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 185 of 363 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Jessamine County. Highest Good-day share: 2020 (95.5%, 232 of 243 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 232 | 11 | 0 | 0 | 37 | 77 |
| 2021 | 211 | 15 | 1 | 0 | 38 | 101 |
| 2022 | 215 | 28 | 0 | 0 | 40 | 87 |
| 2023 | 211 | 32 | 2 | 0 | 43 | 122 |
| 2024 | 200 | 45 | 0 | 0 | 43 | 93 |
| 2025 | 285 | 78 | 0 | 0 | 41 | 100 |
How does Jessamine County compare?
How Jessamine County compares
Good-day share better than US avg
Jessamine County 78.5%
Armstrong County, Pennsylvania 70.5%
US average 76.0%
Median AQI worse than US avg
Jessamine County 41
Armstrong County, Pennsylvania 41
US average 39
Unhealthy days / yr better than US avg
Jessamine County 0
Armstrong County, Pennsylvania 0
US average 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Jessamine County (41), not geographic neighbors.
Armstrong County, Pennsylvania
Median AQI 41 · 70.5% Good-day share
Benewah County, Idaho
Median AQI 41 · 63.4% Good-day share
Berrien County, Michigan
Median AQI 41 · 80.9% Good-day share
Callaway County, Missouri
Median AQI 41 · 89.6% Good-day share
Cambria County, Pennsylvania
Median AQI 41 · 74.5% Good-day share
Cass County, Missouri
Median AQI 41 · 77.6% 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).
McClain County, Oklahoma
78.4% Good-day share · median AQI 43
Iberville County, Louisiana
78.6% Good-day share · median AQI 40
Santa Fe County, New Mexico
78.4% Good-day share · median AQI 44
Warren County, Pennsylvania
78.7% Good-day share · median AQI 35
Gloucester County, New Jersey
78.7% Good-day share · median AQI 39
Ocean County, New Jersey
78.8% 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 Jessamine 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 41 means for exposure. Health guidance
- See how Jessamine County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Jessamine County with its Kentucky neighbours before drawing a conclusion about the region. All of Kentucky
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 Jessamine County, Kentucky? ▼
Jessamine County has a median Air Quality Index (AQI) of 41, rated "Good." 78.5% of monitored days (285 out of 363) had good air quality in 2025.
What is the main pollutant in Jessamine County? ▼
The primary pollutant in Jessamine County is Ozone (O3), which was the main AQI driver on 185 days (51% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Jessamine County have? ▼
In 2025, Jessamine County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 100.
Is the air quality in Jessamine County getting better or worse? ▼
Air quality in Jessamine 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 95.5% (232 of 243 days). Lowest qualifying Good-day share: 2025 at 78.5% (285 of 363 days).
What does AQI 41 mean for health? ▼
Jessamine County's median AQI of 41 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Jessamine County compare to other counties in Kentucky? ▼
Jessamine County has 78.5% 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 Jessamine County? ▼
The 90th percentile AQI for Jessamine County is 57, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 100 (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 Jessamine 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.