Clark, Nevada vs Maricopa, Arizona Air Quality
Side-by-side air quality comparison using 10 years of EPA monitoring data. Clark, Nevada has the edge with an Air Quality Grade of D (43/100).
| Metric | Clark, Nevada | Maricopa, Arizona |
|---|---|---|
| Air Quality Grade | D (43/100) | F (9/100) |
| Current Median AQI | 61 (Moderate) | 72 (Moderate) |
| 5-Year Average AQI | 62 | 90 |
| 10-Year Trend | → Stable (0) | ↑ Worsening (+3) |
| Unhealthy Days/Year | 23 | 126 |
| Primary Pollutant | Ground-Level Ozone | Ground-Level Ozone |
Side-by-Side Analysis
Clark, Nevada outperforms Maricopa, Arizona on overall air quality with a Grade D (43/100) versus F (9/100). Clark, Nevada's 5-year median AQI of 62 sits in the "Moderate" range, while Maricopa, Arizona averages 90 ("Moderate") — a 28-point gap that shows up consistently in year-over-year readings, not just in a single year.
The two cities are moving in opposite directions: Clark, Nevada is stable (+0.2 AQI/yr) while Maricopa, Arizona is worsening (+2.9 AQI/yr). Over time, today's ranking may flip if these trends hold.
What's in the Air
Both cities share the same dominant pollutant: Ground-Level Ozone. These cities' dominant issue is ground-level ozone — formed when sunlight reacts with vehicle and industrial emissions. Ozone peaks on hot, sunny, stagnant summer days and aggravates asthma even in healthy adults exercising outdoors.
Health Implications
Over a 5-year window, Clark, Nevada averages roughly 23 unhealthy air days per year (AQI above 100, where sensitive groups should limit outdoor exertion) versus 126 for Maricopa, Arizona. That 103-day gap matters most for residents with asthma, COPD, heart disease, or pregnancy — and for outdoor workers, who accumulate the most cumulative exposure. The city with fewer unhealthy days offers a meaningfully different baseline risk picture for sensitive populations. For long-term residents, the cleaner-air city is associated with measurably better outcomes on respiratory disease, cardiovascular events, and life expectancy — Harvard cohort research consistently finds 0.5 to 1.0 years of additional life expectancy for each 10-µg/m³ reduction in long-term PM2.5 exposure.
Frequently Asked Questions
Clark, Nevada has better air quality with a Grade D (43/100) compared to Maricopa, Arizona's Grade F (9/100). Clark, Nevada has a current median AQI of 61 and is stable over the past decade.
Clark, Nevada averages 23 unhealthy air days per year (5-year average), while Maricopa, Arizona averages 126. Unhealthy days are those when AQI exceeds 100 and sensitive groups should limit outdoor activity.
Clark, Nevada's primary pollutant is Ground-Level Ozone, while Maricopa, Arizona's is Ground-Level Ozone. Both cities share the same dominant pollutant.
Source: EPA Outdoor Air Quality Data, 2026.
Comparing entity A and entity B on U.S. air quality and AQI history requires lining up the underlying EPA Air Quality System data data side by side. The table above runs the comparison on the canonical fields; the narrative below identifies the factor or factors that drive the most meaningful difference between the two.
For households or analysts using this comparison as a decision input, the right framing is usually not "which is better" in aggregate but "which is better for the specific decision in front of you." EPA Air Quality System data captures the raw data; the framing depends on whether the question is investment, residency, planning, or research.