Median AQI
47
Good
Louisiana · County air quality · 2025
Lafayette County, Louisiana
Median AQI 47 (Good). 61.5% of monitored days rated Good, direct from EPA Air Quality System stations.
- 47
- Median AQI
- 61.5%
- Good-air days
- 0
- Unhealthy days
- 17%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Lafayette County's air is good on balance, among the more polluted 10% of US counties, a median AQI of 47 with 61.5% of 270 monitored days in the Good band, driven mainly by PM2.5.
- 47
- median AQI · Good
- 61.5%
- days rated Good
- PM2.5
- main pollutant
- 17%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 79.
Data updated July 2026
- Good · 166 d · 61.5%
- Moderate · 104 d · 38.5%
How did Lafayette County's air break down in 2025?
Across 270 monitored days, 166 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 79 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 270 days monitored. Median AQI: 47 (Good).
Insights: Lafayette County, Louisiana. EPA monitors recorded a median Air Quality Index of 47 across 270 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 166 (61%) fell in the Good band (AQI 0–50), 104 (39%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 61, while the worst single-day peak hit 79 (Moderate). Residents averaged about 18.4 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (177 days), Ozone (93 days). Across the 2020–2025 trend window, good days shifted by -37 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 79, moderate but never Unhealthy. Nearby counties show comparable readings: Ascension (94.1% good, AQI 33); Bossier (86.5% good, AQI 40); Caddo (84.3% good, AQI 38); Calcasieu (61.5% good, AQI 47); East Baton Rouge (49.3% good, AQI 51); Iberville (78.4% good, AQI 41).
Air Quality Summary
Good Days
61.5%
166 of 270 monitored days
-13.5pp vs 75% target
Max AQI Recorded
79
Moderate
Health Grade
Moderate
90th-pct AQI 61
Lafayette County, Good days share 61.5%
National avg
Share of monitored days at AQI 0-50 (Good band).
Lafayette 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 270 monitored days across EPA AQI categories.
Good
166
61%
Moderate
104
39%
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 Lafayette County.
- PM2.5 · 177 days · 65.6%
- Ozone · 93 days · 34.4%
Health Impact Assessment
Moderate
Lafayette County's air quality is rated Moderate based on 61.5% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 61.5% of monitored days in 2025, with a median AQI of 47. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 177 of 270 monitored days.
5-Year Air Quality Trend
Air quality is improving in Lafayette County. Best year: 2021 (243 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 203 | 160 | 1 | 0 | 45 | 120 |
| 2021 | 243 | 122 | 0 | 0 | 42 | 87 |
| 2022 | 213 | 149 | 2 | 0 | 47 | 103 |
| 2023 | 211 | 153 | 1 | 0 | 47 | 112 |
| 2024 | 180 | 183 | 2 | 0 | 51 | 108 |
| 2025 | 166 | 104 | 0 | 0 | 47 | 79 |
How does Lafayette County compare?
How Lafayette County compares
Good-day share worse than US avg
Lafayette County 61.5%
Ascension County, Louisiana 94.1%
US average 76.5%
Median AQI worse than US avg
Lafayette County 47
Ascension County, Louisiana 33
US average 38
Unhealthy days / yr about average
Lafayette County 0
Ascension County, Louisiana 0
US average 0
Other Counties in Louisiana
Air quality comparison for nearby counties in Louisiana.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Lafayette County.
Beaver County, Pennsylvania
AQI 47 · 54.3% good
Bell County, Texas
AQI 47 · 61.3% good
Bowie County, Texas
AQI 47 · 57.3% good
Bronx County, New York
AQI 47 · 56.6% good
Butte County, California
AQI 47 · 66.1% good
Calcasieu County, Louisiana
AQI 47 · 61.5% good
What Lafayette 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 47 means for exposure. Health guidance
- See how Lafayette County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Lafayette County with its Louisiana neighbours before drawing a conclusion about the region. All of Louisiana
Based on 270 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 Lafayette County, Louisiana? ▼
Lafayette County has a median Air Quality Index (AQI) of 47, rated "Good." 61.5% of monitored days (166 out of 270) had good air quality in 2025.
What is the main pollutant in Lafayette County? ▼
The primary pollutant in Lafayette County is Fine Particles (PM2.5), which was the main AQI driver on 177 days (66% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Lafayette County have? ▼
In 2025, Lafayette County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 79.
Is the air quality in Lafayette County getting better or worse? ▼
Air quality in Lafayette County is improving based on 5-year trends (2020-2025). Best year: 2021 with 243 good days. Worst year: 2025 with 166 good days.
What does AQI 47 mean for health? ▼
Lafayette County's median AQI of 47 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 Lafayette County compare to other counties in Louisiana? ▼
Lafayette County has 61.5% good air days. Nearby counties in Louisiana: Ascension (94.1% good), Bossier (86.5% good), Caddo (84.3% good), Calcasieu (61.5% good), East Baton Rouge (49.3% good), Iberville (78.4% good).
What is the 90th percentile AQI in Lafayette County? ▼
The 90th percentile AQI for Lafayette County is 61, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 79 (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.