Arizona Cities Ranked by Indoor Radon Levels
Measured averages from Airthings devices across Arizona, USA. Action level: 4 pCi/L — the threshold at which remediation is recommended.
Sierra Vista has the highest measured indoor radon in Arizona at 4.0 pCi/L, based on Airthings measurements across 47 cities.
Updated October 19, 2026
Highest city
4.0pCi/L
Sierra Vista
Arizona city average
1.7pCi/L
across 47 cities
Above action level
0/ 47
cities
| # | Location | Avg level | vs action level |
|---|---|---|---|
| 1 | Sierra Vista | 4.0 pCi/L | 1.0× under |
| 2 | Payson | 3.4 pCi/L | 0.8× under |
| 3 | Prescott | 3.2 pCi/L | 0.8× under |
| 4 | Flagstaff | 3.1 pCi/L | 0.8× under |
| 5 | Litchfield Park | 3.1 pCi/L | 0.8× under |
| 6 | Carefree | 3.0 pCi/L | 0.7× under |
| 7 | San Carlos | 2.9 pCi/L | 0.7× under |
| 8 | Scottsdale | 2.5 pCi/L | 0.6× under |
| 9 | Mountainaire | 2.4 pCi/L | 0.6× under |
| 10 | Tempe Junction | 2.2 pCi/L | 0.5× under |
| 11 | Green Valley | 2.1 pCi/L | 0.5× under |
| 12 | Tempe | 2.1 pCi/L | 0.5× under |
| 13 | Sahuarita | 1.9 pCi/L | 0.5× under |
| 14 | Williamson | 1.9 pCi/L | 0.5× under |
| 15 | Tanque Verde | 1.9 pCi/L | 0.5× under |
| 16 | West Sedona | 1.8 pCi/L | 0.5× under |
| 17 | Mesa | 1.8 pCi/L | 0.4× under |
| 18 | Paradise Valley | 1.8 pCi/L | 0.4× under |
| 19 | Fountain Hills | 1.7 pCi/L | 0.4× under |
| 20 | Glendale | 1.7 pCi/L | 0.4× under |
| 21 | Gilbert | 1.6 pCi/L | 0.4× under |
| 22 | Prescott Valley | 1.6 pCi/L | 0.4× under |
| 23 | Kachina Village | 1.6 pCi/L | 0.4× under |
| 24 | Peoria | 1.6 pCi/L | 0.4× under |
| 25 | Queen Creek | 1.5 pCi/L | 0.4× under |
| 26 | Apache Junction | 1.5 pCi/L | 0.4× under |
| 27 | Anthem | 1.4 pCi/L | 0.4× under |
| 28 | Sun Lakes | 1.4 pCi/L | 0.4× under |
| 29 | Maricopa | 1.4 pCi/L | 0.3× under |
| 30 | Goodyear | 1.4 pCi/L | 0.3× under |
| 31 | Tortolita | 1.2 pCi/L | 0.3× under |
| 32 | South Tucson | 1.2 pCi/L | 0.3× under |
| 33 | Catalina Foothills | 1.2 pCi/L | 0.3× under |
| 34 | Casas Adobes | 1.1 pCi/L | 0.3× under |
| 35 | Laveen | 1.1 pCi/L | 0.3× under |
| 36 | Chandler | 1.1 pCi/L | 0.3× under |
| 37 | Sun City | 1.1 pCi/L | 0.3× under |
| 38 | Flowing Wells | 1.0 pCi/L | 0.3× under |
| 39 | Oro Valley | 1.0 pCi/L | 0.3× under |
| 40 | Phoenix | 1.0 pCi/L | 0.2× under |
| 41 | Cave Creek | 0.9 pCi/L | 0.2× under |
| 42 | Guadalupe | 0.9 pCi/L | 0.2× under |
| 43 | Tolleson | 0.9 pCi/L | 0.2× under |
| 44 | Surprise | 0.8 pCi/L | 0.2× under |
| 45 | Tucson | 0.7 pCi/L | 0.2× under |
| 46 | Sun City West | 0.6 pCi/L | 0.1× under |
| 47 | Citrus Park | 0.4 pCi/L | 0.1× under |