Ohio Cities Ranked by Indoor Radon Levels
Measured averages from Airthings devices across Ohio, USA. Action level: 4 pCi/L — the threshold at which remediation is recommended.
Ashville has the highest measured indoor radon in Ohio at 20.3 pCi/L, based on Airthings measurements across 320 cities.
Updated October 19, 2026
Highest city
20.3pCi/L
Ashville
Ohio city average
3.8pCi/L
across 320 cities
Above action level
110/ 320
cities
| # | Location | Avg level | vs action level |
|---|---|---|---|
| 1 | Ashville | 20.3 pCi/L | 5.1× over |
| 2 | Calcutta | 15.6 pCi/L | 3.9× over |
| 3 | Millersburg | 13.4 pCi/L | 3.3× over |
| 4 | North Fork Village | 13.1 pCi/L | 3.3× over |
| 5 | Saint Marys | 12.9 pCi/L | 3.2× over |
| 6 | Danville | 12.3 pCi/L | 3.1× over |
| 7 | Heath | 11.6 pCi/L | 2.9× over |
| 8 | Frazeysburg | 10.0 pCi/L | 2.5× over |
| 9 | Gambier | 9.9 pCi/L | 2.5× over |
| 10 | Bellefontaine | 9.8 pCi/L | 2.4× over |
| 11 | Obetz | 9.7 pCi/L | 2.4× over |
| 12 | Blacklick Estates | 9.3 pCi/L | 2.3× over |
| 13 | Northridge | 9.2 pCi/L | 2.3× over |
| 14 | Mount Vernon | 8.9 pCi/L | 2.2× over |
| 15 | Groveport | 8.6 pCi/L | 2.1× over |
| 16 | Prospect | 8.4 pCi/L | 2.1× over |
| 17 | Reynoldsburg | 8.2 pCi/L | 2.1× over |
| 18 | Commercial Point | 8.2 pCi/L | 2.0× over |
| 19 | Centerburg | 8.0 pCi/L | 2.0× over |
| 20 | Salem Heights | 7.7 pCi/L | 1.9× over |
| 21 | Beechwood Trails | 7.6 pCi/L | 1.9× over |
| 22 | Circleville | 7.5 pCi/L | 1.9× over |
| 23 | Mantua | 7.5 pCi/L | 1.9× over |
| 24 | Harrison | 7.5 pCi/L | 1.9× over |
| 25 | Bellbrook | 7.5 pCi/L | 1.9× over |
| 26 | Granville South | 7.5 pCi/L | 1.9× over |
| 27 | Wilmington | 7.3 pCi/L | 1.8× over |
| 28 | Newark | 7.3 pCi/L | 1.8× over |
| 29 | Lake Darby | 7.2 pCi/L | 1.8× over |
| 30 | Ashley | 7.1 pCi/L | 1.8× over |
| 31 | Vermilion | 6.8 pCi/L | 1.7× over |
| 32 | Tallmadge | 6.8 pCi/L | 1.7× over |
| 33 | Silver Lake | 6.7 pCi/L | 1.7× over |
| 34 | Miamisburg | 6.7 pCi/L | 1.7× over |
| 35 | Port Clinton | 6.7 pCi/L | 1.7× over |
| 36 | Canal Winchester | 6.5 pCi/L | 1.6× over |
| 37 | Monroe | 6.5 pCi/L | 1.6× over |
| 38 | Blanchester | 6.4 pCi/L | 1.6× over |
| 39 | Whitehouse | 6.4 pCi/L | 1.6× over |
| 40 | Wapakoneta | 6.3 pCi/L | 1.6× over |
| 41 | Whitehall | 6.3 pCi/L | 1.6× over |
| 42 | Fairborn | 6.3 pCi/L | 1.6× over |
| 43 | Delaware | 6.2 pCi/L | 1.6× over |
| 44 | Trenton | 6.2 pCi/L | 1.6× over |
| 45 | New Franklin | 6.2 pCi/L | 1.5× over |
| 46 | Norton | 6.1 pCi/L | 1.5× over |
| 47 | Granville | 6.0 pCi/L | 1.5× over |
| 48 | Xenia | 6.0 pCi/L | 1.5× over |
| 49 | New Philadelphia | 6.0 pCi/L | 1.5× over |
| 50 | Gahanna | 5.9 pCi/L | 1.5× over |
| 51 | Pemberville | 5.9 pCi/L | 1.5× over |
| 52 | Johnstown | 5.8 pCi/L | 1.5× over |
| 53 | Ashland | 5.8 pCi/L | 1.5× over |
| 54 | Northwood | 5.8 pCi/L | 1.5× over |
| 55 | Marion | 5.8 pCi/L | 1.4× over |
| 56 | Lincoln Village | 5.7 pCi/L | 1.4× over |
| 57 | Huber Ridge | 5.5 pCi/L | 1.4× over |
| 58 | Urbana | 5.5 pCi/L | 1.4× over |
| 59 | Pickerington | 5.5 pCi/L | 1.4× over |
| 60 | Westerville | 5.5 pCi/L | 1.4× over |
| 61 | Yellow Springs | 5.5 pCi/L | 1.4× over |
| 62 | Worthington | 5.4 pCi/L | 1.4× over |
| 63 | Bluffton | 5.3 pCi/L | 1.3× over |
| 64 | Columbus | 5.2 pCi/L | 1.3× over |
| 65 | Sandusky | 5.2 pCi/L | 1.3× over |
| 66 | Riverside | 5.2 pCi/L | 1.3× over |
| 67 | Minerva Park | 5.1 pCi/L | 1.3× over |
| 68 | Plain City | 5.1 pCi/L | 1.3× over |
| 69 | North Canton | 5.1 pCi/L | 1.3× over |
| 70 | Massillon | 5.1 pCi/L | 1.3× over |
| 71 | Piqua | 5.0 pCi/L | 1.3× over |
| 72 | Vandalia | 5.0 pCi/L | 1.2× over |
| 73 | Leesburg | 4.9 pCi/L | 1.2× over |
| 74 | Wooster | 4.9 pCi/L | 1.2× over |
| 75 | Macedonia | 4.8 pCi/L | 1.2× over |
| 76 | Powell | 4.8 pCi/L | 1.2× over |
| 77 | Jackson | 4.7 pCi/L | 1.2× over |
| 78 | Springfield | 4.7 pCi/L | 1.2× over |
| 79 | Dublin | 4.7 pCi/L | 1.2× over |
| 80 | Perry | 4.6 pCi/L | 1.2× over |
| 81 | Morrow | 4.6 pCi/L | 1.1× over |
| 82 | Lithopolis | 4.6 pCi/L | 1.1× over |
| 83 | Huron | 4.5 pCi/L | 1.1× over |
| 84 | Hunter | 4.4 pCi/L | 1.1× over |
| 85 | Troy | 4.4 pCi/L | 1.1× over |
| 86 | White Oak | 4.4 pCi/L | 1.1× over |
| 87 | Upper Arlington | 4.4 pCi/L | 1.1× over |
| 88 | Highpoint | 4.4 pCi/L | 1.1× over |
| 89 | North Royalton | 4.4 pCi/L | 1.1× over |
| 90 | Tipp City | 4.4 pCi/L | 1.1× over |
| 91 | Bexley | 4.3 pCi/L | 1.1× over |
| 92 | Zanesville | 4.3 pCi/L | 1.1× over |
| 93 | Hilliard | 4.3 pCi/L | 1.1× over |
| 94 | Sunbury | 4.2 pCi/L | 1.1× over |
| 95 | Lebanon | 4.2 pCi/L | 1.1× over |
| 96 | New Richmond | 4.2 pCi/L | 1.1× over |
| 97 | Montrose-Ghent | 4.2 pCi/L | 1.1× over |
| 98 | West Milton | 4.2 pCi/L | 1.1× over |
| 99 | Finneytown | 4.2 pCi/L | 1.1× over |
| 100 | Grove City | 4.2 pCi/L | 1.0× over |
| 101 | Baltimore | 4.2 pCi/L | 1.0× over |
| 102 | New Bremen | 4.1 pCi/L | 1.0× over |
| 103 | Greensburg | 4.1 pCi/L | 1.0× over |
| 104 | Etna | 4.1 pCi/L | 1.0× over |
| 105 | Waterville | 4.1 pCi/L | 1.0× over |
| 106 | Waynesville | 4.1 pCi/L | 1.0× over |
| 107 | Marysville | 4.0 pCi/L | 1.0× over |
| 108 | Springboro | 4.0 pCi/L | 1.0× over |
| 109 | Streetsboro | 4.0 pCi/L | 1.0× over |
| 110 | South Lebanon | 4.0 pCi/L | 1.0× over |
| ✓ Below EPA action level (4 pCi/L) | |||
| 111 | Germantown | 4.0 pCi/L | 1.0× under |
| 112 | Grandview Heights | 4.0 pCi/L | 1.0× under |
| 113 | Louisville | 4.0 pCi/L | 1.0× under |
| 114 | New Albany | 4.0 pCi/L | 1.0× under |
| 115 | Perry Heights | 4.0 pCi/L | 1.0× under |
| 116 | Wintersville | 4.0 pCi/L | 1.0× under |
| 117 | Mount Gilead | 3.9 pCi/L | 1.0× under |
| 118 | Hamilton | 3.9 pCi/L | 1.0× under |
| 119 | Sheffield | 3.9 pCi/L | 1.0× under |
| 120 | West Jefferson | 3.9 pCi/L | 1.0× under |
| 121 | Beachwood | 3.9 pCi/L | 1.0× under |
| 122 | Wetherington | 3.8 pCi/L | 0.9× under |
| 123 | Perrysburg | 3.8 pCi/L | 0.9× under |
| 124 | Findlay | 3.8 pCi/L | 0.9× under |
| 125 | Mulberry | 3.8 pCi/L | 0.9× under |
| 126 | Amelia | 3.8 pCi/L | 0.9× under |
| 127 | Lewis Center | 3.7 pCi/L | 0.9× under |
| 128 | Doylestown | 3.7 pCi/L | 0.9× under |
| 129 | North Olmsted | 3.7 pCi/L | 0.9× under |
| 130 | Williamsburg | 3.7 pCi/L | 0.9× under |
| 131 | Washington Court House | 3.7 pCi/L | 0.9× under |
| 132 | Beavercreek | 3.6 pCi/L | 0.9× under |
| 133 | Fort Shawnee | 3.6 pCi/L | 0.9× under |
| 134 | Lancaster | 3.6 pCi/L | 0.9× under |
| 135 | West Carrollton City | 3.6 pCi/L | 0.9× under |
| 136 | Avon Lake | 3.5 pCi/L | 0.9× under |
| 137 | Canal Fulton | 3.5 pCi/L | 0.9× under |
| 138 | Hillsboro | 3.5 pCi/L | 0.9× under |
| 139 | Kettering | 3.5 pCi/L | 0.9× under |
| 140 | Dry Run | 3.5 pCi/L | 0.9× under |
| 141 | Sidney | 3.5 pCi/L | 0.9× under |
| 142 | Day Heights | 3.4 pCi/L | 0.9× under |
| 143 | Sawyerwood | 3.4 pCi/L | 0.9× under |
| 144 | East Palestine | 3.4 pCi/L | 0.8× under |
| 145 | Avon Center | 3.3 pCi/L | 0.8× under |
| 146 | Greentown | 3.3 pCi/L | 0.8× under |
| 147 | Pataskala | 3.3 pCi/L | 0.8× under |
| 148 | Amberley | 3.3 pCi/L | 0.8× under |
| 149 | Dalton | 3.3 pCi/L | 0.8× under |
| 150 | North Zanesville | 3.3 pCi/L | 0.8× under |
| 151 | Kent | 3.3 pCi/L | 0.8× under |
| 152 | Dover | 3.2 pCi/L | 0.8× under |
| 153 | Paulding | 3.2 pCi/L | 0.8× under |
| 154 | New California | 3.2 pCi/L | 0.8× under |
| 155 | Galion | 3.2 pCi/L | 0.8× under |
| 156 | Uniontown | 3.1 pCi/L | 0.8× under |
| 157 | Green | 3.1 pCi/L | 0.8× under |
| 158 | Norwalk | 3.1 pCi/L | 0.8× under |
| 159 | Saint Bernard | 3.1 pCi/L | 0.8× under |
| 160 | Beckett Ridge | 3.1 pCi/L | 0.8× under |
| 161 | North Ridgeville | 3.1 pCi/L | 0.8× under |
| 162 | Avon | 3.1 pCi/L | 0.8× under |
| 163 | Kings Mills | 3.1 pCi/L | 0.8× under |
| 164 | Oakwood | 3.0 pCi/L | 0.8× under |
| 165 | Sharonville | 3.0 pCi/L | 0.8× under |
| 166 | The Village of Indian Hill | 3.0 pCi/L | 0.8× under |
| 167 | Martins Ferry | 3.0 pCi/L | 0.8× under |
| 168 | Lincoln Heights | 3.0 pCi/L | 0.8× under |
| 169 | Withamsville | 3.0 pCi/L | 0.8× under |
| 170 | Grafton | 3.0 pCi/L | 0.7× under |
| 171 | Loveland | 3.0 pCi/L | 0.7× under |
| 172 | Cleveland | 3.0 pCi/L | 0.7× under |
| 173 | Middletown | 3.0 pCi/L | 0.7× under |
| 174 | Geneva | 2.9 pCi/L | 0.7× under |
| 175 | Bowling Green | 2.9 pCi/L | 0.7× under |
| 176 | Woodville | 2.9 pCi/L | 0.7× under |
| 177 | Mansfield | 2.9 pCi/L | 0.7× under |
| 178 | Oregon | 2.9 pCi/L | 0.7× under |
| 179 | Portage Lakes | 2.9 pCi/L | 0.7× under |
| 180 | New Miami | 2.9 pCi/L | 0.7× under |
| 181 | Maumee | 2.9 pCi/L | 0.7× under |
| 182 | Ontario | 2.9 pCi/L | 0.7× under |
| 183 | Brunswick | 2.8 pCi/L | 0.7× under |
| 184 | Amherst | 2.8 pCi/L | 0.7× under |
| 185 | Defiance | 2.8 pCi/L | 0.7× under |
| 186 | Sixteen Mile Stand | 2.8 pCi/L | 0.7× under |
| 187 | Sylvania | 2.7 pCi/L | 0.7× under |
| 188 | Fairfield | 2.7 pCi/L | 0.7× under |
| 189 | Bay Village | 2.7 pCi/L | 0.7× under |
| 190 | Bethesda | 2.7 pCi/L | 0.7× under |
| 191 | Centerville | 2.7 pCi/L | 0.7× under |
| 192 | Dent | 2.7 pCi/L | 0.7× under |
| 193 | Oxford | 2.7 pCi/L | 0.7× under |
| 194 | Batavia | 2.7 pCi/L | 0.7× under |
| 195 | Mentor-on-the-Lake | 2.7 pCi/L | 0.7× under |
| 196 | Highland Heights | 2.7 pCi/L | 0.7× under |
| 197 | Medina | 2.7 pCi/L | 0.7× under |
| 198 | New Carlisle | 2.7 pCi/L | 0.7× under |
| 199 | Peninsula | 2.7 pCi/L | 0.7× under |
| 200 | Mason | 2.6 pCi/L | 0.7× under |
| 201 | Loveland Park | 2.6 pCi/L | 0.7× under |
| 202 | Northfield | 2.6 pCi/L | 0.7× under |
| 203 | Berea | 2.6 pCi/L | 0.7× under |
| 204 | Akron | 2.6 pCi/L | 0.6× under |
| 205 | Thornport | 2.6 pCi/L | 0.6× under |
| 206 | Mentor | 2.5 pCi/L | 0.6× under |
| 207 | Mogadore | 2.5 pCi/L | 0.6× under |
| 208 | Mariemont | 2.5 pCi/L | 0.6× under |
| 209 | Wadsworth | 2.5 pCi/L | 0.6× under |
| 210 | Lorain | 2.5 pCi/L | 0.6× under |
| 211 | Canton | 2.5 pCi/L | 0.6× under |
| 212 | Cherry Grove | 2.5 pCi/L | 0.6× under |
| 213 | Gnadenhutten | 2.5 pCi/L | 0.6× under |
| 214 | Saint Clairsville | 2.5 pCi/L | 0.6× under |
| 215 | Milford | 2.4 pCi/L | 0.6× under |
| 216 | Boardman | 2.4 pCi/L | 0.6× under |
| 217 | Dayton | 2.4 pCi/L | 0.6× under |
| 218 | Terrace Park | 2.4 pCi/L | 0.6× under |
| 219 | Cuyahoga Falls | 2.4 pCi/L | 0.6× under |
| 220 | Huber Heights | 2.4 pCi/L | 0.6× under |
| 221 | Elida | 2.4 pCi/L | 0.6× under |
| 222 | Eaton Estates | 2.3 pCi/L | 0.6× under |
| 223 | Lexington | 2.3 pCi/L | 0.6× under |
| 224 | Shaker Heights | 2.3 pCi/L | 0.6× under |
| 225 | Montgomery | 2.3 pCi/L | 0.6× under |
| 226 | Willoughby Hills | 2.3 pCi/L | 0.6× under |
| 227 | Athens | 2.3 pCi/L | 0.6× under |
| 228 | Pepper Pike | 2.3 pCi/L | 0.6× under |
| 229 | Franklin | 2.3 pCi/L | 0.6× under |
| 230 | Richfield | 2.3 pCi/L | 0.6× under |
| 231 | Shawnee Hills | 2.3 pCi/L | 0.6× under |
| 232 | Brimfield | 2.3 pCi/L | 0.6× under |
| 233 | Madeira | 2.3 pCi/L | 0.6× under |
| 234 | Middleburg Heights | 2.2 pCi/L | 0.6× under |
| 235 | Rocky River | 2.2 pCi/L | 0.6× under |
| 236 | Mayfield | 2.2 pCi/L | 0.6× under |
| 237 | Broadview Heights | 2.2 pCi/L | 0.6× under |
| 238 | Painesville | 2.2 pCi/L | 0.6× under |
| 239 | Reminderville | 2.2 pCi/L | 0.6× under |
| 240 | Somerset | 2.2 pCi/L | 0.6× under |
| 241 | Strongsville | 2.2 pCi/L | 0.6× under |
| 242 | Boston Heights | 2.2 pCi/L | 0.5× under |
| 243 | Cincinnati | 2.1 pCi/L | 0.5× under |
| 244 | Chardon | 2.1 pCi/L | 0.5× under |
| 245 | Parma Heights | 2.1 pCi/L | 0.5× under |
| 246 | Mount Repose | 2.1 pCi/L | 0.5× under |
| 247 | Independence | 2.1 pCi/L | 0.5× under |
| 248 | Turpin Hills | 2.1 pCi/L | 0.5× under |
| 249 | Bainbridge | 2.1 pCi/L | 0.5× under |
| 250 | Marietta | 2.1 pCi/L | 0.5× under |
| 251 | Blue Ash | 2.1 pCi/L | 0.5× under |
| 252 | Wyoming | 2.0 pCi/L | 0.5× under |
| 253 | Westlake | 2.0 pCi/L | 0.5× under |
| 254 | Delhi Hills | 2.0 pCi/L | 0.5× under |
| 255 | Dry Ridge | 2.0 pCi/L | 0.5× under |
| 256 | Parma | 2.0 pCi/L | 0.5× under |
| 257 | Seven Hills | 2.0 pCi/L | 0.5× under |
| 258 | Brookville | 2.0 pCi/L | 0.5× under |
| 259 | Silverton | 1.9 pCi/L | 0.5× under |
| 260 | Upper Sandusky | 1.9 pCi/L | 0.5× under |
| 261 | Twinsburg | 1.9 pCi/L | 0.5× under |
| 262 | Willoughby | 1.9 pCi/L | 0.5× under |
| 263 | Mack | 1.8 pCi/L | 0.5× under |
| 264 | Olmsted Falls | 1.8 pCi/L | 0.5× under |
| 265 | Sheffield Lake | 1.8 pCi/L | 0.5× under |
| 266 | Ottawa Hills | 1.8 pCi/L | 0.4× under |
| 267 | Ross | 1.8 pCi/L | 0.4× under |
| 268 | Richmond Heights | 1.8 pCi/L | 0.4× under |
| 269 | Stow | 1.8 pCi/L | 0.4× under |
| 270 | Landen | 1.8 pCi/L | 0.4× under |
| 271 | Hudson | 1.7 pCi/L | 0.4× under |
| 272 | Holland | 1.7 pCi/L | 0.4× under |
| 273 | Chagrin Falls | 1.7 pCi/L | 0.4× under |
| 274 | Fairlawn | 1.7 pCi/L | 0.4× under |
| 275 | Poland | 1.7 pCi/L | 0.4× under |
| 276 | Elyria | 1.6 pCi/L | 0.4× under |
| 277 | Canfield | 1.6 pCi/L | 0.4× under |
| 278 | Sherwood | 1.6 pCi/L | 0.4× under |
| 279 | Aurora | 1.6 pCi/L | 0.4× under |
| 280 | Brecksville | 1.6 pCi/L | 0.4× under |
| 281 | Dillonvale | 1.5 pCi/L | 0.4× under |
| 282 | East Cleveland | 1.5 pCi/L | 0.4× under |
| 283 | Lyndhurst | 1.5 pCi/L | 0.4× under |
| 284 | Garfield Heights | 1.5 pCi/L | 0.4× under |
| 285 | Walton Hills | 1.5 pCi/L | 0.4× under |
| 286 | Evendale | 1.5 pCi/L | 0.4× under |
| 287 | Mayfield Heights | 1.5 pCi/L | 0.4× under |
| 288 | Ravenna | 1.5 pCi/L | 0.4× under |
| 289 | Brooklyn | 1.5 pCi/L | 0.4× under |
| 290 | Five Points | 1.5 pCi/L | 0.4× under |
| 291 | Solon | 1.5 pCi/L | 0.4× under |
| 292 | Chesterland | 1.4 pCi/L | 0.4× under |
| 293 | Genoa | 1.4 pCi/L | 0.3× under |
| 294 | Youngstown | 1.4 pCi/L | 0.3× under |
| 295 | Orange | 1.4 pCi/L | 0.3× under |
| 296 | Fairfax | 1.4 pCi/L | 0.3× under |
| 297 | South Point | 1.3 pCi/L | 0.3× under |
| 298 | Fairport Harbor | 1.3 pCi/L | 0.3× under |
| 299 | Cleveland Heights | 1.3 pCi/L | 0.3× under |
| 300 | Norwood | 1.2 pCi/L | 0.3× under |
| 301 | South Russell | 1.2 pCi/L | 0.3× under |
| 302 | Wright-Patterson AFB | 1.2 pCi/L | 0.3× under |
| 303 | Gates Mills | 1.2 pCi/L | 0.3× under |
| 304 | Euclid | 1.1 pCi/L | 0.3× under |
| 305 | Bratenahl | 1.1 pCi/L | 0.3× under |
| 306 | Lordstown | 1.1 pCi/L | 0.3× under |
| 307 | Fairview Park | 1.1 pCi/L | 0.3× under |
| 308 | Englewood | 1.1 pCi/L | 0.3× under |
| 309 | University Heights | 1.1 pCi/L | 0.3× under |
| 310 | Lakewood | 1.1 pCi/L | 0.3× under |
| 311 | Columbiana | 1.1 pCi/L | 0.3× under |
| 312 | Austintown | 1.0 pCi/L | 0.3× under |
| 313 | Toledo | 1.0 pCi/L | 0.2× under |
| 314 | Fort McKinley | 0.9 pCi/L | 0.2× under |
| 315 | Cheviot | 0.9 pCi/L | 0.2× under |
| 316 | Kirtland | 0.9 pCi/L | 0.2× under |
| 317 | Edgewood | 0.8 pCi/L | 0.2× under |
| 318 | Yorkville | 0.8 pCi/L | 0.2× under |
| 319 | Moreland Hills | 0.7 pCi/L | 0.2× under |
| 320 | Willowick | 0.6 pCi/L | 0.2× under |