Median AQI
50
Good
Louisiana · County air quality · 2025
West Baton Rouge County, Louisiana
Median AQI 50 (Good). 50.5% of monitored days rated Good, direct from EPA Air Quality System stations.
- 50
- Median AQI
- 50.5%
- Good-air days
- 0
- Unhealthy days
- 7%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, West Baton Rouge County's air is good on balance, among the most polluted counties nationally, a median AQI of 50 with 50.5% of 273 monitored days in the Good band, driven mainly by PM2.5.
- 50
- median AQI · Good
- 50.5%
- days rated Good
- PM2.5
- main pollutant
- 7%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 112.
Data updated July 2026
- Good · 138 d · 50.5%
- Moderate · 134 d · 49.1%
- USG · 1 d · 0.4%
How did West Baton Rouge County's air break down in 2025?
Across 273 monitored days, 138 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 112 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 273 days monitored. Median AQI: 50 (Good).
Insights: West Baton Rouge County, Louisiana. EPA monitors recorded a median Air Quality Index of 50 across 273 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 138 (51%) fell in the Good band (AQI 0–50), 134 (49%) registered Moderate readings, and 1 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 61, while the worst single-day peak hit 112 (USG). Residents averaged about 15.2 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (209 days), Ozone (64 days). Across the 2020–2025 trend window, good days shifted by -91 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 112, usg 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
50.5%
138 of 273 monitored days
-24.5pp vs 75% target
Max AQI Recorded
112
USG
Health Grade
Moderate
90th-pct AQI 61
West Baton Rouge County, Good days share 50.5%
National avg
Share of monitored days at AQI 0-50 (Good band).
West Baton Rouge 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 273 monitored days across EPA AQI categories.
Good
138
51%
Moderate
134
49%
USG
1
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 West Baton Rouge County.
- PM2.5 · 209 days · 76.6%
- Ozone · 64 days · 23.4%
Health Impact Assessment
Moderate
West Baton Rouge County's air quality is rated Moderate based on 50.5% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 50.5% of monitored days in 2025, with a median AQI of 50. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 209 of 273 monitored days.
5-Year Air Quality Trend
Air quality is worsening in West Baton Rouge County. Best year: 2020 (229 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 229 | 134 | 3 | 0 | 44 | 101 |
| 2021 | 220 | 142 | 3 | 0 | 46 | 150 |
| 2022 | 216 | 144 | 4 | 0 | 46 | 105 |
| 2023 | 154 | 199 | 9 | 0 | 52 | 140 |
| 2024 | 198 | 166 | 2 | 0 | 49 | 101 |
| 2025 | 138 | 134 | 1 | 0 | 50 | 112 |
How does West Baton Rouge County compare?
How West Baton Rouge County compares
Good-day share worse than US avg
West Baton Rouge County 50.5%
Ascension County, Louisiana 94.1%
US average 76.5%
Median AQI worse than US avg
West Baton Rouge County 50
Ascension County, Louisiana 33
US average 38
Unhealthy days / yr about average
West Baton Rouge 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 West Baton Rouge County.
Adams County, Colorado
AQI 50 · 50.2% good
Albany County, Wyoming
AQI 50 · 51.9% good
Boulder County, Colorado
AQI 50 · 50.9% good
Davidson County, North Carolina
AQI 50 · 50.2% good
Davidson County, Tennessee
AQI 50 · 51.8% good
Gila County, Arizona
AQI 50 · 52.0% good
What West Baton Rouge 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 50 means for exposure. Health guidance
- See how West Baton Rouge County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare West Baton Rouge County with its Louisiana neighbours before drawing a conclusion about the region. All of Louisiana
Based on 273 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 West Baton Rouge County, Louisiana? ▼
West Baton Rouge County has a median Air Quality Index (AQI) of 50, rated "Good." 50.5% of monitored days (138 out of 273) had good air quality in 2025.
What is the main pollutant in West Baton Rouge County? ▼
The primary pollutant in West Baton Rouge County is Fine Particles (PM2.5), which was the main AQI driver on 209 days (77% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does West Baton Rouge County have? ▼
In 2025, West Baton Rouge County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 112.
Is the air quality in West Baton Rouge County getting better or worse? ▼
Air quality in West Baton Rouge County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 229 good days. Worst year: 2025 with 138 good days.
What does AQI 50 mean for health? ▼
West Baton Rouge County's median AQI of 50 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 West Baton Rouge County compare to other counties in Louisiana? ▼
West Baton Rouge County has 50.5% 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 West Baton Rouge County? ▼
The 90th percentile AQI for West Baton Rouge County is 61, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 112 (USG).
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.