Median AQI
51
Moderate
Louisiana · County air quality · 2025
West Baton Rouge County, Louisiana
Median AQI 51 (Moderate). 49.3% of monitored days rated Good, direct from EPA Air Quality System stations.
- 51
- Median AQI
- 49.3%
- Good-air days
- 0
- Unhealthy days
- 6%
- Cleaner than US counties
West Baton Rouge County's 2025 annual median AQI is 51 (Moderate), with 49.3% Good days
According to the U.S. EPA Air Quality System, West Baton Rouge County, Louisiana posted a 2025 median AQI of 51 (Moderate) across 365 monitored days, with 49.3% 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
- West Baton Rouge County's 49.3% Good-day share places it cleaner than 6% of US counties in 2025.
- Closest median-AQI peer
- Davidson County (45.8% Good, median AQI 51) is the closest nationwide median-AQI peer to West Baton Rouge County.
- 2020–2025 trend
- West Baton Rouge County's floor-qualifying Good-day share is worsening from 2020 to 2025 (62.6% → 49.3%).
- Median AQI
- Median AQI: 51
The verdict
According to EPA Air Quality System monitoring data, West Baton Rouge County's air is moderate on balance, among the most polluted counties nationally, a median AQI of 51 with 49.3% of 365 monitored days in the Good band, driven mainly by PM2.5.
- 51
- median AQI · Moderate
- 49.3%
- days rated Good
- PM2.5
- main pollutant
- 6%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 122.
Annual release change
What changed in the 2025 EPA annual release
- West Baton Rouge County's Good-day share fell from 54.1% to 49.3% between the 2024 and 2025 EPA annual releases, a change of -4.8 percentage points.
- West Baton Rouge County's peak single-day AQI rose from 101 to 122 between the 2024 and 2025 EPA annual releases, a change of +21 points.
Data updated August 2026
- Good · 180 d · 49.3%
- Moderate · 183 d · 50.1%
- USG · 2 d · 0.5%
How did West Baton Rouge County's air break down in 2025?
Across 365 monitored days, 180 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 122 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 365 days monitored. Median AQI: 51 (Moderate).
Insights: West Baton Rouge County, Louisiana. EPA monitors recorded a median Air Quality Index of 51 across 365 measured days in 2025, earning a Moderate classification and a Poor health grade. Of those days, 180 (49%) fell in the Good band (AQI 0–50), 183 (50%) registered Moderate readings, and 2 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 61, while the worst single-day peak hit 122 (USG). Residents averaged about 14.8 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (285 days), Ozone (80 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -13.3 points and the median AQI moved +7 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 122, usg but never Unhealthy. Nearby counties show comparable readings: Ascension (95.6% good, AQI 33); Bossier (78.9% good, AQI 42); Caddo (80.0% good, AQI 38); Calcasieu (62.2% good, AQI 47); East Baton Rouge (49.6% good, AQI 51); Iberville (78.6% good, AQI 40).
Air Quality Summary
Good Days
49.3%
180 of 365 monitored days
-25.7pp vs 75% target
Max AQI Recorded
122
USG
Health Grade
Poor
90th-pct AQI 61
West Baton Rouge County, Good days share 49.3%
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 365 monitored days across EPA AQI categories.
Good
180
49%
Moderate
183
50%
USG
2
1%
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 · 285 days · 78.1%
- Ozone · 80 days · 21.9%
Health Impact Assessment
Poor
West Baton Rouge County's air quality is rated Poor based on 49.3% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 49.3% of monitored days in 2025, with a median AQI of 51. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 285 of 365 monitored days.
5-Year Air Quality Trend
Air quality is worsening in West Baton Rouge County. Highest Good-day share: 2020 (62.6%, 229 of 366 monitored 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 | 180 | 183 | 2 | 0 | 51 | 122 |
How does West Baton Rouge County compare?
How West Baton Rouge County compares
Good-day share worse than typical
West Baton Rouge County 49.3%
Davidson County, North Carolina 45.8%
Typical US county 76.0%
Median AQI worse than typical
West Baton Rouge County 51
Davidson County, North Carolina 51
Typical US county 39
Unhealthy days / yr better than typical
West Baton Rouge County 0
Davidson County, North Carolina 0
Typical US county 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as West Baton Rouge County (51), not geographic neighbors.
Davidson County, North Carolina
Median AQI 51 · 45.8% Good-day share
Duval County, Florida
Median AQI 51 · 48.0% Good-day share
East Baton Rouge County, Louisiana
Median AQI 51 · 49.6% Good-day share
Garland County, Arkansas
Median AQI 51 · 49.2% Good-day share
Jefferson County, Texas
Median AQI 51 · 48.0% Good-day share
McLennan County, Texas
Median AQI 51 · 46.6% Good-day share
Same primary pollutant: PM2.5
PM2.5 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).
Oklahoma County, Oklahoma
49.9% Good-day share · median AQI 51
Webb County, Texas
49.9% Good-day share · median AQI 51
New York County, New York
50.1% Good-day share · median AQI 50
Philadelphia County, Pennsylvania
50.4% Good-day share · median AQI 50
Mecklenburg County, North Carolina
48.2% Good-day share · median AQI 51
Tulsa County, Oklahoma
50.7% Good-day share · median AQI 50
Louisiana counties on the map
Geographic containment only, other monitored counties in Louisiana, independent of AQI or pollutant match.
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 51 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 365 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 West Baton Rouge County, Louisiana? ▼
West Baton Rouge County has a median Air Quality Index (AQI) of 51, rated "Moderate." 49.3% of monitored days (180 out of 365) 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 285 days (78% 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 122.
Is the air quality in West Baton Rouge County getting better or worse? ▼
Air quality in West Baton Rouge 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 62.6% (229 of 366 days). Lowest qualifying Good-day share: 2023 at 42.5% (154 of 362 days).
What does AQI 51 mean for health? ▼
West Baton Rouge County's median AQI of 51 falls in the "Moderate" category. See the AQI category guide for what each range means for health.
How does West Baton Rouge County compare to other counties in Louisiana? ▼
West Baton Rouge County has 49.3% good air days. Nearby counties in Louisiana: Ascension (95.6% good), Bossier (78.9% good), Caddo (80.0% good), Calcasieu (62.2% good), East Baton Rouge (49.6% good), Iberville (78.6% 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 122 (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. Spotted a figure that looks wrong? Report a correction.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for West Baton Rouge County, Louisiana · 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.