Out of 1,056 ZIP codes with data in Iowa, these are the lowest-ranked areas for radon zone. See also: National ZIP Codes with Highest Radon Risk | All Iowa Rankings
| Statistic | Value |
|---|---|
| ZIP codes ranked | 1,056 |
| Lowest value | Zone 1 (High) |
| Median value | Zone 1 (High) |
| State | Iowa |
100 Lowest-Ranked ZIP Codes
| Rank | ZIP Code | City | State | Radon Zone | Safety Score |
|---|---|---|---|---|---|
| 1 | 50133 | Kellerton | IA | Zone 1 (High) | 30/100 |
| 2 | 51462 | Scranton | IA | Zone 1 (High) | 30/100 |
| 3 | 50128 | Jamaica | IA | Zone 1 (High) | 32/100 |
| 4 | 52642 | Rome | IA | Zone 1 (High) | 33/100 |
| 5 | 50635 | Gladbrook | IA | Zone 1 (High) | 34/100 |
| 6 | 50669 | Reinbeck | IA | Zone 1 (High) | 34/100 |
| 7 | 50501 | Fort Dodge | IA | Zone 1 (High) | 35/100 |
| 8 | 50112 | Grinnell | IA | Zone 1 (High) | 36/100 |
| 9 | 50522 | Burt | IA | Zone 1 (High) | 36/100 |
| 10 | 50539 | Fenton | IA | Zone 1 (High) | 36/100 |
| 11 | 52163 | Protivin | IA | Zone 1 (High) | 36/100 |
| 12 | 50001 | Ackworth | IA | Zone 1 (High) | 40/100 |
| 13 | 50007 | Alleman | IA | Zone 1 (High) | 40/100 |
| 14 | 50026 | Bagley | IA | Zone 1 (High) | 40/100 |
| 15 | 50031 | Beaver | IA | Zone 1 (High) | 40/100 |
| 16 | 50033 | Bevington | IA | Zone 1 (High) | 40/100 |
| 17 | 50040 | Boxholm | IA | Zone 1 (High) | 40/100 |
| 18 | 50041 | Bradford | IA | Zone 1 (High) | 40/100 |
| 19 | 50043 | Buckeye | IA | Zone 1 (High) | 40/100 |
| 20 | 50052 | Clio | IA | Zone 1 (High) | 40/100 |
| 21 | 50057 | Columbia | IA | Zone 1 (High) | 40/100 |
| 22 | 50059 | Cooper | IA | Zone 1 (High) | 40/100 |
| 23 | 50064 | Dana | IA | Zone 1 (High) | 40/100 |
| 24 | 50065 | Davis City | IA | Zone 1 (High) | 40/100 |
| 25 | 50067 | Decatur | IA | Zone 1 (High) | 40/100 |
| 26 | 50068 | Derby | IA | Zone 1 (High) | 40/100 |
| 27 | 50074 | Ellston | IA | Zone 1 (High) | 40/100 |
| 28 | 50078 | Ferguson | IA | Zone 1 (High) | 40/100 |
| 29 | 50101 | Galt | IA | Zone 1 (High) | 40/100 |
| 30 | 50102 | Garden City | IA | Zone 1 (High) | 40/100 |
| 31 | 50104 | Gibson | IA | Zone 1 (High) | 40/100 |
| 32 | 50108 | Grand River | IA | Zone 1 (High) | 40/100 |
| 33 | 50110 | Gray | IA | Zone 1 (High) | 40/100 |
| 34 | 50116 | Hamilton | IA | Zone 1 (High) | 40/100 |
| 35 | 50117 | Hamlin | IA | Zone 1 (High) | 40/100 |
| 36 | 50120 | Haverhill | IA | Zone 1 (High) | 40/100 |
| 37 | 50127 | Ira | IA | Zone 1 (High) | 40/100 |
| 38 | 50132 | Kamrar | IA | Zone 1 (High) | 40/100 |
| 39 | 50137 | Killduff | IA | Zone 1 (High) | 40/100 |
| 40 | 50143 | Leighton | IA | Zone 1 (High) | 40/100 |
| 41 | 50145 | Liberty Center | IA | Zone 1 (High) | 40/100 |
| 42 | 50146 | Linden | IA | Zone 1 (High) | 40/100 |
| 43 | 50149 | Lorimor | IA | Zone 1 (High) | 40/100 |
| 44 | 50154 | Mc Callsburg | IA | Zone 1 (High) | 40/100 |
| 45 | 50155 | Macksburg | IA | Zone 1 (High) | 40/100 |
| 46 | 50164 | Menlo | IA | Zone 1 (High) | 40/100 |
| 47 | 50165 | Millerton | IA | Zone 1 (High) | 40/100 |
| 48 | 50217 | Paton | IA | Zone 1 (High) | 40/100 |
| 49 | 50222 | Peru | IA | Zone 1 (High) | 40/100 |
| 50 | 50227 | Popejoy | IA | Zone 1 (High) | 40/100 |
| 51 | 50235 | Rippey | IA | Zone 1 (High) | 40/100 |
| 52 | 50239 | Saint Anthony | IA | Zone 1 (High) | 40/100 |
| 53 | 50242 | Searsboro | IA | Zone 1 (High) | 40/100 |
| 54 | 50254 | Thayer | IA | Zone 1 (High) | 40/100 |
| 55 | 50255 | Thornburg | IA | Zone 1 (High) | 40/100 |
| 56 | 50259 | Gifford | IA | Zone 1 (High) | 40/100 |
| 57 | 50262 | Van Wert | IA | Zone 1 (High) | 40/100 |
| 58 | 50264 | Weldon | IA | Zone 1 (High) | 40/100 |
| 59 | 50269 | Whitten | IA | Zone 1 (High) | 40/100 |
| 60 | 50272 | Williamson | IA | Zone 1 (High) | 40/100 |
| 61 | 50275 | Woodburn | IA | Zone 1 (High) | 40/100 |
| 62 | 50426 | Carpenter | IA | Zone 1 (High) | 40/100 |
| 63 | 50427 | Chapin | IA | Zone 1 (High) | 40/100 |
| 64 | 50433 | Dougherty | IA | Zone 1 (High) | 40/100 |
| 65 | 50454 | Little Cedar | IA | Zone 1 (High) | 40/100 |
| 66 | 50455 | Mc Intire | IA | Zone 1 (High) | 40/100 |
| 67 | 50467 | Rock Falls | IA | Zone 1 (High) | 40/100 |
| 68 | 50473 | Scarville | IA | Zone 1 (High) | 40/100 |
| 69 | 50515 | Ayrshire | IA | Zone 1 (High) | 40/100 |
| 70 | 50520 | Bradgate | IA | Zone 1 (High) | 40/100 |
| 71 | 50521 | Burnside | IA | Zone 1 (High) | 40/100 |
| 72 | 50527 | Curlew | IA | Zone 1 (High) | 40/100 |
| 73 | 50528 | Cylinder | IA | Zone 1 (High) | 40/100 |
| 74 | 50545 | Hardy | IA | Zone 1 (High) | 40/100 |
| 75 | 50567 | Nemaha | IA | Zone 1 (High) | 40/100 |
| 76 | 50607 | Aurora | IA | Zone 1 (High) | 40/100 |
| 77 | 50608 | Austinville | IA | Zone 1 (High) | 40/100 |
| 78 | 50612 | Buckingham | IA | Zone 1 (High) | 40/100 |
| 79 | 50649 | Kesley | IA | Zone 1 (High) | 40/100 |
| 80 | 50652 | Lincoln | IA | Zone 1 (High) | 40/100 |
| 81 | 50654 | Masonville | IA | Zone 1 (High) | 40/100 |
| 82 | 50657 | Morrison | IA | Zone 1 (High) | 40/100 |
| 83 | 50661 | North Washington | IA | Zone 1 (High) | 40/100 |
| 84 | 50664 | Oran | IA | Zone 1 (High) | 40/100 |
| 85 | 50667 | Raymond | IA | Zone 1 (High) | 40/100 |
| 86 | 50671 | Stanley | IA | Zone 1 (High) | 40/100 |
| 87 | 50830 | Afton | IA | Zone 1 (High) | 40/100 |
| 88 | 50831 | Arispe | IA | Zone 1 (High) | 40/100 |
| 89 | 50835 | Benton | IA | Zone 1 (High) | 40/100 |
| 90 | 50836 | Blockton | IA | Zone 1 (High) | 40/100 |
| 91 | 50837 | Bridgewater | IA | Zone 1 (High) | 40/100 |
| 92 | 50839 | Carbon | IA | Zone 1 (High) | 40/100 |
| 93 | 50840 | Clearfield | IA | Zone 1 (High) | 40/100 |
| 94 | 50842 | Cromwell | IA | Zone 1 (High) | 40/100 |
| 95 | 50847 | Grant | IA | Zone 1 (High) | 40/100 |
| 96 | 50848 | Gravity | IA | Zone 1 (High) | 40/100 |
| 97 | 50857 | Nodaway | IA | Zone 1 (High) | 40/100 |
| 98 | 50859 | Prescott | IA | Zone 1 (High) | 40/100 |
| 99 | 50860 | Redding | IA | Zone 1 (High) | 40/100 |
| 100 | 50861 | Shannon City | IA | Zone 1 (High) | 40/100 |
Methodology
Radon rankings are based on EPA county-level radon zone classifications. Zone 1 (highest risk) has predicted average indoor radon levels above 4 pCi/L — the EPA action level. Zone 2 is moderate (2-4 pCi/L) and Zone 3 is low (below 2 pCi/L). Within Zone 1, ZIP codes are sub-ranked by Home Safety Score to prioritize areas with compounding risk factors.
Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-06-04.
Frequently Asked Questions
What is EPA Radon Zone 1?
Zone 1 is the EPA highest-risk classification, meaning the county has predicted average indoor radon levels above 4 pCi/L — the level at which the EPA recommends mitigation. Radon causes about 21,000 lung cancer deaths per year in the U.S.
Should I test for radon?
The EPA recommends testing all homes regardless of radon zone. A DIY test kit costs $15-40. Professional testing costs $150-250. If levels exceed 4 pCi/L, mitigation systems ($800-2,500) can reduce radon by up to 99%.
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