Kentucky · County air quality · 2025

Jessamine County, Kentucky

Median AQI 41 (Good). 78.8% of monitored days rated Good, direct from EPA Air Quality System stations.

41
Median AQI
78.8%
Good-air days
0
Unhealthy days
48%
Cleaner than US counties

The verdict

According to EPA Air Quality System monitoring data, Jessamine County's air is good on balance, more polluted than the median US county, a median AQI of 41 with 78.8% of 179 monitored days in the Good band, driven mainly by PM2.5.

41
median AQI · Good
78.8%
days rated Good
PM2.5
main pollutant
48%
cleaner than US counties

Not one day crossed into the Unhealthy tier; the worst single reading was AQI 72.

Data updated July 2026

Jessamine County AQI category distribution Stacked-segment bar showing the share of monitored days that fell in each EPA AQI category, Good, Moderate, USG, Unhealthy, Very Unhealthy, Hazardous, with median AQI marker. AQI category distribution 179 monitored days G M Median AQI 41 0 50 100 150 200 300 500 Jessamine County
  • Good · 141 d · 78.8%
  • Moderate · 38 d · 21.2%

How did Jessamine County's air break down in 2025?

Across 179 monitored days, 141 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 72 (Moderate).

EPA AQS →

Air quality data from EPA Air Quality System (2025). 179 days monitored. Median AQI: 41 (Good).

Insights: Jessamine County, Kentucky. EPA monitors recorded a median Air Quality Index of 41 across 179 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 141 (79%) fell in the Good band (AQI 0–50), 38 (21%) 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 72 (Moderate). Residents averaged about 23.6 clean-air days per 30-day window during the monitoring year.

The full pollutant mix ranks as PM2.5 (92 days), Ozone (87 days). Across the 2020–2025 trend window, good days shifted by -91 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 72, 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

Median AQI

41

Good

Good Days

78.8%

141 of 179 monitored days

3.8pp vs 75% target

Max AQI Recorded

72

Moderate

Health Grade

Good

90th-pct AQI 56

Jessamine County, Good days share 78.8%
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 179 monitored days across EPA AQI categories.

Good

141

79%

Moderate

38

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.

Jessamine County, Kentucky criteria pollutant distribution Stratified-band visualization showing the share of monitored days each criteria pollutant (PM2.5, PM10, O3, NO2, CO) was the primary AQI driver. PM2.5 · 51.4% Ozone · 48.6% 0% 25% 50% 75% 100% Jessamine County, Kentucky · 179 monitored days Criteria pollutant column
  • PM2.5 · 92 days · 51.4%
  • Ozone · 87 days · 48.6%
Fine Particles (PM2.5) 92 days (51%)

How PM2.5 affects health →

Ozone (O3) 87 days (49%)

How Ozone affects health →

Health Impact Assessment

Good

Jessamine County's air quality is rated Good based on 78.8% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 78.8% 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 PM2.5, driving AQI on 92 of 179 monitored days.

5-Year Air Quality Trend

Air quality is worsening in Jessamine County. Best year: 2020 (232 good days).

Year Good Moderate USG Unhealthy Median AQI
2020 232 11 0 0 37
2021 211 15 1 0 38
2022 215 28 0 0 40
2023 211 32 2 0 43
2024 200 45 0 0 43
2025 141 38 0 0 41

How does Jessamine County compare?

How Jessamine County compares

Good-day share better than US avg
Jessamine County 78.8%
Bell County, Kentucky 63.5%
US average 76.5%
Median AQI worse than US avg
Jessamine County 41
Bell County, Kentucky 43
US average 38
Unhealthy days / yr about average
Jessamine 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 Jessamine County.

What Jessamine 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 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 179 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 Jessamine County, Kentucky?
Jessamine County has a median Air Quality Index (AQI) of 41, rated "Good." 78.8% of monitored days (141 out of 179) had good air quality in 2025.
What is the main pollutant in Jessamine County?
The primary pollutant in Jessamine County is Fine Particles (PM2.5), which was the main AQI driver on 92 days (51% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
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 72.
Is the air quality in Jessamine County getting better or worse?
Air quality in Jessamine County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 232 good days. Worst year: 2025 with 141 good days.
What does AQI 41 mean for health?
Jessamine County's median AQI of 41 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 Jessamine County compare to other counties in Kentucky?
Jessamine County has 78.8% 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 Jessamine County?
The 90th percentile AQI for Jessamine County is 56, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 72 (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.