Median AQI
47
Good
Arizona · County air quality · 2025
La Paz County, Arizona
Median AQI 47 (Good). 68.6% of monitored days rated Good, direct from EPA Air Quality System stations.
- 47
- Median AQI
- 68.6%
- Good-air days
- 1
- Unhealthy days
- 29%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, La Paz County's air is good on balance, more polluted than the median US county, a median AQI of 47 with 68.6% of 271 monitored days in the Good band, driven mainly by Ozone.
- 47
- median AQI · Good
- 68.6%
- days rated Good
- Ozone
- main pollutant
- 29%
- cleaner than US counties
1 day reached Unhealthy or worse; the worst single reading hit AQI 253.
Data updated July 2026
- Good · 186 d · 68.6%
- Moderate · 84 d · 31.0%
- Very Unhealthy · 1 d · 0.4%
How did La Paz County's air break down in 2025?
Across 271 monitored days, 186 fell in the Good band (AQI 0–50) and 1 reached Unhealthy or worse. The worst single day peaked at AQI 253 (Very Unhealthy).
EPA AQS →Air quality data from EPA Air Quality System (2025). 271 days monitored. Median AQI: 47 (Good).
Insights: La Paz County, Arizona. EPA monitors recorded a median Air Quality Index of 47 across 271 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 186 (69%) fell in the Good band (AQI 0–50), 84 (31%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 71, while the worst single-day peak hit 253 (Very Unhealthy). Residents averaged about 20.6 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (246 days), PM2.5 (15 days), PM10 (10 days). Across the 2020–2025 trend window, good days shifted by -106 and the median AQI moved +3 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: Apache (99.6% good, AQI 14); Cochise (65.6% good, AQI 46); Coconino (62.5% good, AQI 48); Gila (52.0% good, AQI 50); Maricopa (16.4% good, AQI 71); Mohave (93.4% good, AQI 19).
Air Quality Summary
Good Days
68.6%
186 of 271 monitored days
-6.4pp vs 75% target
Max AQI Recorded
253
Very Unhealthy
Health Grade
Moderate
90th-pct AQI 71
La Paz County, Good days share 68.6%
National avg
Share of monitored days at AQI 0-50 (Good band).
La Paz 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 271 monitored days across EPA AQI categories.
Good
186
69%
Moderate
84
31%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
1
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in La Paz County.
- Ozone · 246 days · 90.8%
- PM2.5 · 15 days · 5.5%
- PM10 · 10 days · 3.7%
Health Impact Assessment
Moderate
La Paz County's air quality is rated Moderate based on 68.6% good air days. There were 1 unhealthy days in 2025 when outdoor activity should be limited.
Air quality reached unhealthy levels on 1 days in 2025 (0 Unhealthy, 1 Very Unhealthy). Sensitive groups, including people with asthma, COPD, cardiovascular conditions, children, and adults over 65, should review the daily breakdown below and follow local air-quality advisories on high-AQI days.
Sensitive group advisory
People with asthma, COPD, heart disease, children, pregnant women, and adults 65+ should follow EPA AQI alerts daily and limit outdoor exertion when AQI exceeds 100. Real-time conditions: airnow.gov.
The dominant pollutant is Ozone, driving AQI on 246 of 271 monitored days.
5-Year Air Quality Trend
Air quality is worsening in La Paz County. Best year: 2020 (292 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 292 | 72 | 2 | 0 | 44 | 125 |
| 2021 | 254 | 107 | 0 | 1 | 46 | 187 |
| 2022 | 275 | 83 | 1 | 0 | 44 | 130 |
| 2023 | 257 | 104 | 3 | 0 | 45 | 126 |
| 2024 | 224 | 135 | 4 | 0 | 47 | 105 |
| 2025 | 186 | 84 | 0 | 0 | 47 | 253 |
How does La Paz County compare?
How La Paz County compares
Good-day share worse than US avg
La Paz County 68.6%
Apache County, Arizona 99.6%
US average 76.5%
Median AQI worse than US avg
La Paz County 47
Apache County, Arizona 14
US average 38
Unhealthy days / yr worse than US avg
La Paz County 1
Apache County, Arizona 0
US average 0
Other Counties in Arizona
Air quality comparison for nearby counties in Arizona.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to La Paz 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 La Paz 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 47 means for exposure. Health guidance
- See how La Paz County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare La Paz County with its Arizona neighbours before drawing a conclusion about the region. All of Arizona
Based on 271 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 La Paz County, Arizona? ▼
La Paz County has a median Air Quality Index (AQI) of 47, rated "Good." 68.6% of monitored days (186 out of 271) had good air quality in 2025.
What is the main pollutant in La Paz County? ▼
The primary pollutant in La Paz County is Ozone (O3), which was the main AQI driver on 246 days (91% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does La Paz County have? ▼
In 2025, La Paz County recorded 1 unhealthy air days (0 Unhealthy, 1 Very Unhealthy, 0 Hazardous). The maximum AQI reached 253.
Is the air quality in La Paz County getting better or worse? ▼
Air quality in La Paz County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 292 good days. Worst year: 2025 with 186 good days.
What does AQI 47 mean for health? ▼
La Paz 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 La Paz County compare to other counties in Arizona? ▼
La Paz County has 68.6% good air days. Nearby counties in Arizona: Apache (99.6% good), Cochise (65.6% good), Coconino (62.5% good), Gila (52.0% good), Maricopa (16.4% good), Mohave (93.4% good).
What is the 90th percentile AQI in La Paz County? ▼
The 90th percentile AQI for La Paz County is 71, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 253 (Very 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.