Iowa Cities Ranked by Indoor Radon Levels
Measured averages from Airthings devices across Iowa, USA. Action level: 4 pCi/L — the threshold at which remediation is recommended.
Atlantic has the highest measured indoor radon in Iowa at 12.7 pCi/L, based on Airthings measurements across 128 cities.
Updated September 28, 2026
Highest city
12.7pCi/L
Atlantic
Iowa city average
4.6pCi/L
across 128 cities
Above action level
71/ 128
cities
| # | Location | Avg level | vs action level |
|---|---|---|---|
| 1 | Atlantic | 12.7 pCi/L | 3.2× over |
| 2 | Spencer | 10.3 pCi/L | 2.6× over |
| 3 | Grinnell | 9.8 pCi/L | 2.5× over |
| 4 | Dallas Center | 9.7 pCi/L | 2.4× over |
| 5 | Spirit Lake | 9.5 pCi/L | 2.4× over |
| 6 | Osage | 9.4 pCi/L | 2.3× over |
| 7 | Denison | 9.3 pCi/L | 2.3× over |
| 8 | Onawa | 8.7 pCi/L | 2.2× over |
| 9 | Adel | 8.6 pCi/L | 2.2× over |
| 10 | Arnolds Park | 8.6 pCi/L | 2.1× over |
| 11 | Red Oak | 8.0 pCi/L | 2.0× over |
| 12 | Pella | 7.7 pCi/L | 1.9× over |
| 13 | Carlisle | 7.3 pCi/L | 1.8× over |
| 14 | Boone | 7.2 pCi/L | 1.8× over |
| 15 | Greenfield | 7.2 pCi/L | 1.8× over |
| 16 | Carroll | 7.0 pCi/L | 1.7× over |
| 17 | Tipton | 6.9 pCi/L | 1.7× over |
| 18 | Hartley | 6.7 pCi/L | 1.7× over |
| 19 | Shenandoah | 6.5 pCi/L | 1.6× over |
| 20 | Polk City | 6.3 pCi/L | 1.6× over |
| 21 | Sioux City | 6.3 pCi/L | 1.6× over |
| 22 | Eagle Grove | 6.2 pCi/L | 1.6× over |
| 23 | Baxter | 6.2 pCi/L | 1.5× over |
| 24 | Clinton | 6.1 pCi/L | 1.5× over |
| 25 | Oskaloosa | 6.1 pCi/L | 1.5× over |
| 26 | Fort Dodge | 6.0 pCi/L | 1.5× over |
| 27 | Pleasant Hill | 6.0 pCi/L | 1.5× over |
| 28 | Perry | 6.0 pCi/L | 1.5× over |
| 29 | Le Mars | 5.9 pCi/L | 1.5× over |
| 30 | Urbandale | 5.8 pCi/L | 1.4× over |
| 31 | Humboldt | 5.6 pCi/L | 1.4× over |
| 32 | Milford | 5.5 pCi/L | 1.4× over |
| 33 | Slater | 5.5 pCi/L | 1.4× over |
| 34 | Indianola | 5.4 pCi/L | 1.4× over |
| 35 | Lake View | 5.4 pCi/L | 1.3× over |
| 36 | Anamosa | 5.3 pCi/L | 1.3× over |
| 37 | Jewell | 5.3 pCi/L | 1.3× over |
| 38 | Newton | 5.3 pCi/L | 1.3× over |
| 39 | Manchester | 5.2 pCi/L | 1.3× over |
| 40 | Winterset | 5.2 pCi/L | 1.3× over |
| 41 | Johnston | 5.2 pCi/L | 1.3× over |
| 42 | Clive | 5.2 pCi/L | 1.3× over |
| 43 | Windsor Heights | 5.2 pCi/L | 1.3× over |
| 44 | Des Moines | 5.1 pCi/L | 1.3× over |
| 45 | Altoona | 5.1 pCi/L | 1.3× over |
| 46 | Granger | 5.1 pCi/L | 1.3× over |
| 47 | Huxley | 5.0 pCi/L | 1.3× over |
| 48 | Clarinda | 5.0 pCi/L | 1.3× over |
| 49 | Cherokee | 5.0 pCi/L | 1.3× over |
| 50 | Corydon | 5.0 pCi/L | 1.3× over |
| 51 | Solon | 5.0 pCi/L | 1.2× over |
| 52 | Jefferson | 5.0 pCi/L | 1.2× over |
| 53 | New Hampton | 5.0 pCi/L | 1.2× over |
| 54 | Dakota City | 4.9 pCi/L | 1.2× over |
| 55 | Roland | 4.8 pCi/L | 1.2× over |
| 56 | Garner | 4.8 pCi/L | 1.2× over |
| 57 | Madrid | 4.6 pCi/L | 1.2× over |
| 58 | Northwood | 4.6 pCi/L | 1.2× over |
| 59 | Malvern | 4.6 pCi/L | 1.1× over |
| 60 | Norwalk | 4.6 pCi/L | 1.1× over |
| 61 | Nevada | 4.5 pCi/L | 1.1× over |
| 62 | Sergeant Bluff | 4.5 pCi/L | 1.1× over |
| 63 | Marshalltown | 4.5 pCi/L | 1.1× over |
| 64 | Griswold | 4.3 pCi/L | 1.1× over |
| 65 | Dyersville | 4.2 pCi/L | 1.1× over |
| 66 | Waterloo | 4.2 pCi/L | 1.1× over |
| 67 | Independence | 4.2 pCi/L | 1.0× over |
| 68 | Council Bluffs | 4.2 pCi/L | 1.0× over |
| 69 | Pleasantville | 4.0 pCi/L | 1.0× over |
| 70 | Webster City | 4.0 pCi/L | 1.0× over |
| 71 | Ottumwa | 4.0 pCi/L | 1.0× over |
| ✓ Below EPA action level (4 pCi/L) | |||
| 72 | Burlington | 3.9 pCi/L | 1.0× under |
| 73 | Monticello | 3.9 pCi/L | 1.0× under |
| 74 | Algona | 3.8 pCi/L | 1.0× under |
| 75 | Evansdale | 3.8 pCi/L | 0.9× under |
| 76 | Carter Lake | 3.8 pCi/L | 0.9× under |
| 77 | West Branch | 3.8 pCi/L | 0.9× under |
| 78 | Grimes | 3.7 pCi/L | 0.9× under |
| 79 | Bondurant | 3.7 pCi/L | 0.9× under |
| 80 | Centerville | 3.7 pCi/L | 0.9× under |
| 81 | Mount Vernon | 3.7 pCi/L | 0.9× under |
| 82 | Center Point | 3.6 pCi/L | 0.9× under |
| 83 | Ankeny | 3.6 pCi/L | 0.9× under |
| 84 | Ames | 3.5 pCi/L | 0.9× under |
| 85 | Mitchellville | 3.5 pCi/L | 0.9× under |
| 86 | West Des Moines | 3.5 pCi/L | 0.9× under |
| 87 | Ely | 3.4 pCi/L | 0.9× under |
| 88 | Grundy Center | 3.4 pCi/L | 0.9× under |
| 89 | Charles City | 3.4 pCi/L | 0.9× under |
| 90 | Jesup | 3.4 pCi/L | 0.9× under |
| 91 | Fort Madison | 3.4 pCi/L | 0.8× under |
| 92 | Cedar Falls | 3.3 pCi/L | 0.8× under |
| 93 | Eldridge | 3.3 pCi/L | 0.8× under |
| 94 | Glenwood | 3.3 pCi/L | 0.8× under |
| 95 | Forest City | 3.3 pCi/L | 0.8× under |
| 96 | Waukee | 3.2 pCi/L | 0.8× under |
| 97 | Cresco | 3.2 pCi/L | 0.8× under |
| 98 | Dubuque | 3.2 pCi/L | 0.8× under |
| 99 | Saylorville | 3.1 pCi/L | 0.8× under |
| 100 | De Witt | 3.1 pCi/L | 0.8× under |
| 101 | Mason City | 3.0 pCi/L | 0.8× under |
| 102 | Clear Lake | 2.9 pCi/L | 0.7× under |
| 103 | Eldora | 2.9 pCi/L | 0.7× under |
| 104 | University Heights | 2.9 pCi/L | 0.7× under |
| 105 | Decorah | 2.8 pCi/L | 0.7× under |
| 106 | Asbury | 2.8 pCi/L | 0.7× under |
| 107 | Bettendorf | 2.7 pCi/L | 0.7× under |
| 108 | Iowa City | 2.7 pCi/L | 0.7× under |
| 109 | Marion | 2.6 pCi/L | 0.7× under |
| 110 | Davenport | 2.5 pCi/L | 0.6× under |
| 111 | Hiawatha | 2.5 pCi/L | 0.6× under |
| 112 | Coralville | 2.3 pCi/L | 0.6× under |
| 113 | Robins | 2.3 pCi/L | 0.6× under |
| 114 | Guttenberg | 2.2 pCi/L | 0.6× under |
| 115 | Fairfield | 2.2 pCi/L | 0.5× under |
| 116 | Osceola | 2.1 pCi/L | 0.5× under |
| 117 | Oakland | 2.1 pCi/L | 0.5× under |
| 118 | Muscatine | 2.0 pCi/L | 0.5× under |
| 119 | Cedar Rapids | 2.0 pCi/L | 0.5× under |
| 120 | Tiffin | 2.0 pCi/L | 0.5× under |
| 121 | North Liberty | 1.9 pCi/L | 0.5× under |
| 122 | Fairfax | 1.8 pCi/L | 0.5× under |
| 123 | Albia | 1.8 pCi/L | 0.4× under |
| 124 | Gilbert | 1.7 pCi/L | 0.4× under |
| 125 | Le Claire | 1.7 pCi/L | 0.4× under |
| 126 | Waverly | 1.5 pCi/L | 0.4× under |
| 127 | Buffalo | 1.4 pCi/L | 0.3× under |
| 128 | Central City | 0.8 pCi/L | 0.2× under |