Metro area air quality · 2025

Elizabethtown-Fort Knox, KY

Median AQI 43 (Good). 73.4% of monitored days rated Good across this metro's EPA monitoring network.

43
Median AQI
73.4%
Good-air days
0
Unhealthy days
52%
Cleaner than US metros

Elizabethtown-Fort Knox, KY posted a 2025 median AQI of 43 (Good) with 73.4% Good days

According to the U.S. EPA Air Quality System, the Elizabethtown-Fort Knox, KY CBSA recorded a median AQI of 43 across 304 monitored days in 2025, with 73.4% rated Good and 0 unhealthy or worse. This is an annual metro comparison, not a live advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US metros
The Elizabethtown-Fort Knox, KY CBSA's 73.4% Good-day share places it cleaner than 52% of US metros in 2025.
Closest median-AQI peer
Ashtabula, OH (81.2% Good, median AQI 43) is the closest nationwide median-AQI peer to Elizabethtown-Fort Knox, KY.
2020–2025 Good-day shift
Elizabethtown-Fort Knox, KY's Good-day share moved +0.1 points from 2020 to 2025 (median AQI +0).
Median AQI
Median AQI: 43

Aggregated from EPA Air Quality System (2025), 304 monitored days. EPA AQS →

The verdict

Elizabethtown-Fort Knox, KY's Good-day share (73.4%) sits in the middle CBSA tercile on this extract. On the EPA scale the metro runs good, cleaner than the median US metro, with a median AQI of 43 and 73.4% of 304 monitored days in the Good band.

43
median AQI · Good
73.4%
days rated Good
52%
cleaner than US metros
97
worst single reading

No day crossed into the Unhealthy tier across the metro's monitors in 2025.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Elizabethtown-Fort Knox, KY metro's Good-day share fell from 83.8% to 73.4% between the 2024 and 2025 EPA annual releases, a change of -10.4 percentage points.
  • Elizabethtown-Fort Knox, KY metro's peak single-day AQI rose from 67 to 97 between the 2024 and 2025 EPA annual releases, a change of +30 points.

Compared against 154 monitored days in 2024 and 304 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Elizabethtown-Fort Knox, KY's Good-day share (73.4%) sits in the middle CBSA tercile on this extract. Signature read: 73.4% Good-day share (mid tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 43 over 304 measured days in 2025 (Good / Moderate). The monitored-day split lands at 223 Good (73%), 81 Moderate (27%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 58; the highest single-day reading hit 97 (Moderate).

Across 2020–2025, Good-day share shifted +0.1 points and median AQI moved +0 (stable). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Ashtabula, OH (81.2% good, AQI 43); Bloomington, IN (67.7% good, AQI 43); Champaign-Urbana, IL (65.8% good, AQI 43).

Understanding AQI →

Air Quality Summary

Median AQI

43

Good

Good Days

73.4%

223 of 304 days

Max AQI

97

Moderate

Health Grade

Moderate

90th pct: 58

AQI Day Breakdown (2025)

Distribution of 304 monitored days across EPA AQI categories.

Good

223

73%

Moderate

81

27%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The Elizabethtown-Fort Knox, KY metro area's air quality is rated Moderate based on 73.4% good air days. No unhealthy air days were recorded in 2025.

Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.

How does the Elizabethtown-Fort Knox, KY metro compare?

How Elizabethtown-Fort Knox, KY compares

Good-day share better than typical
Elizabethtown-Fort Knox, KY 73.4%
Ashtabula, OH 81.2%
Typical US metro 70.6%
Median AQI worse than typical
Elizabethtown-Fort Knox, KY 43
Ashtabula, OH 43
Typical US metro 41
Unhealthy days / yr better than typical
Elizabethtown-Fort Knox, KY 0
Ashtabula, OH 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is stable in the Elizabethtown-Fort Knox, KY metro. Highest Good-day share: 2024 (83.8%, 129 of 154 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 268 98 0 43
2021 238 125 0 43
2022 242 120 0 44
2023 225 136 1 45
2024 129 25 0 41
2025 223 81 0 43

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Elizabethtown-Fort Knox, KY (43).

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Elizabethtown-Fort Knox, KY's 0 (independent of median AQI).

Frequently Asked Questions

How many unhealthy air days does Elizabethtown-Fort Knox, KY have?
In 2025, the Elizabethtown-Fort Knox, KY metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 97.
What is the air quality in the Elizabethtown-Fort Knox, KY metro area?
The Elizabethtown-Fort Knox, KY metro area has a median Air Quality Index (AQI) of 43, rated "Good." 73.4% of monitored days (223 out of 304) had good air quality in 2025.
Is air quality in Elizabethtown-Fort Knox, KY getting better or worse?
Air quality in the Elizabethtown-Fort Knox, KY metro is stable across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2024 at 83.8% (129 of 154 days). Lowest qualifying Good-day share: 2023 at 62.2% (225 of 362 days).
What does AQI 43 mean for health?
An AQI of 43 is "Good", air quality is satisfactory and poses little or no health risk. This is the best category on the EPA's AQI scale.
How does Elizabethtown-Fort Knox, KY compare to other metro areas?
The Elizabethtown-Fort Knox, KY metro has 73.4% good air days. Similar metros: Ashtabula, OH (81.2% good), Bloomington, IN (67.7% good), Champaign-Urbana, IL (65.8% good).
What is the 90th percentile AQI for Elizabethtown-Fort Knox, KY?
The 90th percentile AQI for the Elizabethtown-Fort Knox, KY metro area 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 CBSA dataset for Elizabethtown-Fort Knox, KY, 2025. See our methodology for how AQI, median, and coverage figures are computed.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary, Elizabethtown-Fort Knox, KY · 2020–2025