Denver vs Phoenix
The Verdict
Denver is the clear winner with significantly better air quality (32% higher score) compared to Phoenix.
Phoenix, AZ
Grade CDenver vs Phoenix - Common Questions
Is Denver or Phoenix better for air quality?
Denver has better air quality with a Clean Air Score of 79.7 compared to Phoenix's score of 60.2. Denver has 32% cleaner air overall, making it a better choice for people with respiratory concerns or those prioritizing long-term health.
What is the difference in PM2.5 levels between Denver and Phoenix?
Denver has an annual PM2.5 level of 6.6 μg/m³, while Phoenix has 9.3 μg/m³. The WHO recommends keeping PM2.5 below 5.0 μg/m³ for optimal health.
Which city is safer for someone with asthma or allergies?
Denver is generally safer for people with asthma or allergies due to its better air quality score and lower percentage of unhealthy air days (0% vs 0.5%). However, both cities may have seasonal variations that affect air quality.
How does air quality affect property values in these cities?
Cities with better air quality often see 3-7% higher property values compared to areas with poor air quality. Denver's superior air quality may contribute to stronger real estate appreciation over time, while also reducing healthcare costs for residents.
Compare Other Cities
About This Data
Data Sources
Historical air quality mapping and scoring are based completely on official U.S. Environmental Protection Agency (EPA) AirNow API data. 5-day AQI forecasts are provided by WAQI.
Methodology
Our Clean Air Score (0-100) is a proprietary algorithm that weighs multiple factors:
- Annual PM2.5 averages (40%)
- Frequency of unhealthy days (25%)
- 5-year pollution trends (20%)
- Seasonal variability and extreme events (15%)
Updates & Accuracy
Real-time data is updated hourly. Historical aggregate scores are recalculated monthly to reflect the latest trends. While we strive for accuracy, sensor maintenance and local conditions can affect individual readings.
Practical Advice
When AQI > 100: Sensitive groups (children, elderly, asthmatics) should limit prolonged outdoor exertion.
When AQI > 150: Everyone should avoid outdoor exercise and keep windows closed.