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.
The side-by-side above pulls the EPA Air Quality System data data for both Clark, Nevada and Maricopa, Arizona. What follows is the interpretation — which specific axes carry the most weight for Clark, Nevada versus Maricopa, Arizona, and which differences are large enough to influence a real decision.
Practical use of the comparison: read the data above, then drill into the individual Clark, Nevada and Maricopa, Arizona detail pages for the underlying breakdown. A pairwise comparison answers the relative question; the per-entity pages answer the absolute question.