Median AQI
44
Good
Indiana · County air quality · 2025
LaPorte County, Indiana
Median AQI 44 (Good). 62.3% of monitored days rated Good, direct from EPA Air Quality System stations.
- 44
- Median AQI
- 62.3%
- Good-air days
- 1
- Unhealthy days
- 19%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, LaPorte County's air is good on balance, among the more polluted 10% of US counties, a median AQI of 44 with 62.3% of 273 monitored days in the Good band, driven mainly by Ozone.
- 44
- median AQI · Good
- 62.3%
- days rated Good
- Ozone
- main pollutant
- 19%
- cleaner than US counties
1 day reached Unhealthy or worse; the worst single reading hit AQI 153.
Data updated July 2026
- Good · 170 d · 62.3%
- Moderate · 91 d · 33.3%
- USG · 11 d · 4.0%
- Unhealthy · 1 d · 0.4%
How did LaPorte County's air break down in 2025?
Across 273 monitored days, 170 fell in the Good band (AQI 0–50) and 1 reached Unhealthy or worse. The worst single day peaked at AQI 153 (Unhealthy).
EPA AQS →Air quality data from EPA Air Quality System (2025). 273 days monitored. Median AQI: 44 (Good).
Insights: LaPorte County, Indiana. EPA monitors recorded a median Air Quality Index of 44 across 273 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 170 (62%) fell in the Good band (AQI 0–50), 91 (33%) registered Moderate readings, and 11 (4%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 74, while the worst single-day peak hit 153 (Unhealthy). Residents averaged about 18.7 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (153 days), PM2.5 (120 days). Across the 2020–2025 trend window, good days shifted by -121 and the median AQI moved +6 points, placing the multi-year trajectory at worsening. Residents and visitors experienced 1 unhealthy-or-worse days combined, periods when the EPA recommends sensitive groups limit prolonged outdoor exertion. Nearby counties show comparable readings: Allen (58.2% good, AQI 45); Bartholomew (69.2% good, AQI 44); Boone (86.9% good, AQI 38); Brown (94.5% good, AQI 37); Carroll (87.8% good, AQI 37); Clark (59.7% good, AQI 46).
Air Quality Summary
Good Days
62.3%
170 of 273 monitored days
-12.7pp vs 75% target
Max AQI Recorded
153
Unhealthy
Health Grade
Moderate
90th-pct AQI 74
LaPorte County, Good days share 62.3%
National avg
Share of monitored days at AQI 0-50 (Good band).
LaPorte County, Unhealthy-or-worse share 0.4%
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
170
62%
Moderate
91
33%
USG
11
4%
Unhealthy
1
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in LaPorte County.
- Ozone · 153 days · 56.0%
- PM2.5 · 120 days · 44.0%
Health Impact Assessment
Moderate
LaPorte County's air quality is rated Moderate based on 62.3% good air days. There were 1 unhealthy days in 2025 when outdoor activity should be limited.
Air quality is acceptable most days, but 11 days reached "Unhealthy for Sensitive Groups" (AQI 101-150) and peak AQI reached 153. Sensitive groups should monitor real-time conditions at AirNow.gov.
The dominant pollutant is Ozone, driving AQI on 153 of 273 monitored days.
5-Year Air Quality Trend
Air quality is worsening in LaPorte County. Best year: 2022 (302 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 291 | 68 | 6 | 1 | 38 | 154 |
| 2021 | 282 | 78 | 5 | 0 | 37 | 143 |
| 2022 | 302 | 60 | 3 | 0 | 36 | 133 |
| 2023 | 277 | 76 | 12 | 0 | 39 | 133 |
| 2024 | 257 | 107 | 2 | 0 | 41 | 115 |
| 2025 | 170 | 91 | 11 | 1 | 44 | 153 |
How does LaPorte County compare?
How LaPorte County compares
Good-day share worse than US avg
LaPorte County 62.3%
Allen County, Indiana 58.2%
US average 76.5%
Median AQI worse than US avg
LaPorte County 44
Allen County, Indiana 45
US average 38
Unhealthy days / yr worse than US avg
LaPorte County 1
Allen County, Indiana 0
US average 0
Other Counties in Indiana
Air quality comparison for nearby counties in Indiana.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to LaPorte County.
Baltimore County, Maryland
AQI 44 · 70.4% good
Baltimore (City) County, Maryland
AQI 44 · 68.7% good
Bartholomew County, Indiana
AQI 44 · 69.2% good
Berks County, Pennsylvania
AQI 44 · 65.6% good
Bolivar County, Mississippi
AQI 44 · 70.3% good
Brewster County, Texas
AQI 44 · 69.0% good
What LaPorte County's air means for you
On most days the air here is fine, but Ozone drives 1 unhealthy-or-worse day a year that sensitive groups should plan around.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-Ozone days, the guide explains what a median of 44 means for exposure. Health guidance
- See how LaPorte County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare LaPorte County with its Indiana neighbours before drawing a conclusion about the region. All of Indiana
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 LaPorte County, Indiana? ▼
LaPorte County has a median Air Quality Index (AQI) of 44, rated "Good." 62.3% of monitored days (170 out of 273) had good air quality in 2025.
What is the main pollutant in LaPorte County? ▼
The primary pollutant in LaPorte County is Ozone (O3), which was the main AQI driver on 153 days (56% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does LaPorte County have? ▼
In 2025, LaPorte County recorded 1 unhealthy air days (1 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 153.
Is the air quality in LaPorte County getting better or worse? ▼
Air quality in LaPorte County is worsening based on 5-year trends (2020-2025). Best year: 2022 with 302 good days. Worst year: 2025 with 170 good days.
What does AQI 44 mean for health? ▼
LaPorte County's median AQI of 44 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 LaPorte County compare to other counties in Indiana? ▼
LaPorte County has 62.3% good air days. Nearby counties in Indiana: Allen (58.2% good), Bartholomew (69.2% good), Boone (86.9% good), Brown (94.5% good), Carroll (87.8% good), Clark (59.7% good).
What is the 90th percentile AQI in LaPorte County? ▼
The 90th percentile AQI for LaPorte County is 74, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 153 (Unhealthy).
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.