Out of 1,056 ZIP codes with data in Iowa, these are the lowest-ranked areas for radon zone. See also: National ZIP Codes in EPA Radon Zone 1 | All Iowa Rankings
| Statistic | Value |
|---|---|
| ZIP codes ranked | 1,056 |
| Lowest value | Zone 1 (highest potential) |
| Median value | Zone 1 (highest potential) |
| State | Iowa |
100 Lowest-Ranked ZIP Codes
| Rank | ZIP Code | City | State | Radon Zone | Safety Score |
|---|---|---|---|---|---|
| 1 | 52722 | Bettendorf | IA | Zone 1 (highest potential) | 45/100 |
| 2 | 52726 | Blue Grass | IA | Zone 1 (highest potential) | 48/100 |
| 3 | 50677 | Waverly | IA | Zone 1 (highest potential) | 49/100 |
| 4 | 50701 | Waterloo | IA | Zone 1 (highest potential) | 49/100 |
| 5 | 51101 | Sioux City | IA | Zone 1 (highest potential) | 49/100 |
| 6 | 51103 | Sioux City | IA | Zone 1 (highest potential) | 49/100 |
| 7 | 51104 | Sioux City | IA | Zone 1 (highest potential) | 49/100 |
| 8 | 51105 | Sioux City | IA | Zone 1 (highest potential) | 49/100 |
| 9 | 51106 | Sioux City | IA | Zone 1 (highest potential) | 49/100 |
| 10 | 51108 | Sioux City | IA | Zone 1 (highest potential) | 49/100 |
| 11 | 52753 | Le Claire | IA | Zone 1 (highest potential) | 49/100 |
| 12 | 50702 | Waterloo | IA | Zone 1 (highest potential) | 50/100 |
| 13 | 50703 | Waterloo | IA | Zone 1 (highest potential) | 50/100 |
| 14 | 50707 | Evansdale | IA | Zone 1 (highest potential) | 50/100 |
| 15 | 52732 | Clinton | IA | Zone 1 (highest potential) | 50/100 |
| 16 | 52761 | Muscatine | IA | Zone 1 (highest potential) | 50/100 |
| 17 | 52801 | Davenport | IA | Zone 1 (highest potential) | 50/100 |
| 18 | 52802 | Davenport | IA | Zone 1 (highest potential) | 50/100 |
| 19 | 52803 | Davenport | IA | Zone 1 (highest potential) | 50/100 |
| 20 | 52804 | Davenport | IA | Zone 1 (highest potential) | 50/100 |
| 21 | 52806 | Davenport | IA | Zone 1 (highest potential) | 50/100 |
| 22 | 52807 | Davenport | IA | Zone 1 (highest potential) | 50/100 |
| 23 | 52411 | Cedar Rapids | IA | Zone 1 (highest potential) | 55/100 |
| 24 | 52240 | Iowa City | IA | Zone 1 (highest potential) | 57/100 |
| 25 | 51510 | Carter Lake | IA | Zone 1 (highest potential) | 61/100 |
| 26 | 52245 | Iowa City | IA | Zone 1 (highest potential) | 62/100 |
| 27 | 50322 | Urbandale | IA | Zone 1 (highest potential) | 63/100 |
| 28 | 52246 | Iowa City | IA | Zone 1 (highest potential) | 63/100 |
| 29 | 50111 | Grimes | IA | Zone 1 (highest potential) | 64/100 |
| 30 | 50237 | Runnells | IA | Zone 1 (highest potential) | 64/100 |
| 31 | 50501 | Fort Dodge | IA | Zone 1 (highest potential) | 64/100 |
| 32 | 50009 | Altoona | IA | Zone 1 (highest potential) | 65/100 |
| 33 | 50327 | Pleasant Hill | IA | Zone 1 (highest potential) | 65/100 |
| 34 | 50109 | Granger | IA | Zone 1 (highest potential) | 66/100 |
| 35 | 50131 | Johnston | IA | Zone 1 (highest potential) | 66/100 |
| 36 | 50651 | La Porte City | IA | Zone 1 (highest potential) | 66/100 |
| 37 | 51054 | Sergeant Bluff | IA | Zone 1 (highest potential) | 66/100 |
| 38 | 51521 | Avoca | IA | Zone 1 (highest potential) | 66/100 |
| 39 | 51566 | Red Oak | IA | Zone 1 (highest potential) | 66/100 |
| 40 | 51577 | Walnut | IA | Zone 1 (highest potential) | 66/100 |
| 41 | 52314 | Mount Vernon | IA | Zone 1 (highest potential) | 66/100 |
| 42 | 52317 | North Liberty | IA | Zone 1 (highest potential) | 66/100 |
| 43 | 52324 | Palo | IA | Zone 1 (highest potential) | 66/100 |
| 44 | 52404 | Cedar Rapids | IA | Zone 1 (highest potential) | 66/100 |
| 45 | 52405 | Cedar Rapids | IA | Zone 1 (highest potential) | 66/100 |
| 46 | 52748 | Eldridge | IA | Zone 1 (highest potential) | 66/100 |
| 47 | 50007 | Alleman | IA | Zone 1 (highest potential) | 67/100 |
| 48 | 50021 | Ankeny | IA | Zone 1 (highest potential) | 67/100 |
| 49 | 50023 | Ankeny | IA | Zone 1 (highest potential) | 67/100 |
| 50 | 50035 | Bondurant | IA | Zone 1 (highest potential) | 67/100 |
| 51 | 50054 | Colfax | IA | Zone 1 (highest potential) | 67/100 |
| 52 | 50073 | Elkhart | IA | Zone 1 (highest potential) | 67/100 |
| 53 | 50226 | Polk City | IA | Zone 1 (highest potential) | 67/100 |
| 54 | 50243 | Sheldahl | IA | Zone 1 (highest potential) | 67/100 |
| 55 | 50265 | West Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 56 | 50309 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 57 | 50310 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 58 | 50311 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 59 | 50312 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 60 | 50313 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 61 | 50314 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 62 | 50315 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 63 | 50316 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 64 | 50317 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 65 | 50319 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 66 | 50320 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 67 | 50321 | Des Moines | IA | Zone 1 (highest potential) | 67/100 |
| 68 | 50323 | Urbandale | IA | Zone 1 (highest potential) | 67/100 |
| 69 | 50324 | Windsor Heights | IA | Zone 1 (highest potential) | 67/100 |
| 70 | 50325 | Clive | IA | Zone 1 (highest potential) | 67/100 |
| 71 | 50523 | Callender | IA | Zone 1 (highest potential) | 67/100 |
| 72 | 50530 | Dayton | IA | Zone 1 (highest potential) | 67/100 |
| 73 | 50532 | Duncombe | IA | Zone 1 (highest potential) | 67/100 |
| 74 | 50536 | Emmetsburg | IA | Zone 1 (highest potential) | 67/100 |
| 75 | 50543 | Gowrie | IA | Zone 1 (highest potential) | 67/100 |
| 76 | 50544 | Harcourt | IA | Zone 1 (highest potential) | 67/100 |
| 77 | 50557 | Lehigh | IA | Zone 1 (highest potential) | 67/100 |
| 78 | 50566 | Moorland | IA | Zone 1 (highest potential) | 67/100 |
| 79 | 50569 | Otho | IA | Zone 1 (highest potential) | 67/100 |
| 80 | 50613 | Cedar Falls | IA | Zone 1 (highest potential) | 67/100 |
| 81 | 50622 | Denver | IA | Zone 1 (highest potential) | 67/100 |
| 82 | 50647 | Janesville | IA | Zone 1 (highest potential) | 67/100 |
| 83 | 50648 | Jesup | IA | Zone 1 (highest potential) | 67/100 |
| 84 | 50674 | Sumner | IA | Zone 1 (highest potential) | 67/100 |
| 85 | 50676 | Tripoli | IA | Zone 1 (highest potential) | 67/100 |
| 86 | 51501 | Council Bluffs | IA | Zone 1 (highest potential) | 67/100 |
| 87 | 51503 | Council Bluffs | IA | Zone 1 (highest potential) | 67/100 |
| 88 | 51534 | Glenwood | IA | Zone 1 (highest potential) | 67/100 |
| 89 | 51576 | Underwood | IA | Zone 1 (highest potential) | 67/100 |
| 90 | 52227 | Ely | IA | Zone 1 (highest potential) | 67/100 |
| 91 | 52233 | Hiawatha | IA | Zone 1 (highest potential) | 67/100 |
| 92 | 52241 | Coralville | IA | Zone 1 (highest potential) | 67/100 |
| 93 | 52242 | Iowa City | IA | Zone 1 (highest potential) | 67/100 |
| 94 | 52302 | Marion | IA | Zone 1 (highest potential) | 67/100 |
| 95 | 52328 | Robins | IA | Zone 1 (highest potential) | 67/100 |
| 96 | 52352 | Walker | IA | Zone 1 (highest potential) | 67/100 |
| 97 | 52401 | Cedar Rapids | IA | Zone 1 (highest potential) | 67/100 |
| 98 | 52402 | Cedar Rapids | IA | Zone 1 (highest potential) | 67/100 |
| 99 | 52403 | Cedar Rapids | IA | Zone 1 (highest potential) | 67/100 |
| 100 | 52535 | Birmingham | IA | Zone 1 (highest potential) | 67/100 |
Methodology
This ranking is limited to EPA county-level radon zone classification. Zone 1 identifies the highest county-level potential category; it does not measure a home or establish whether any building is above an action level. Within Zone 1, ZIP codes are sub-ranked by Home Safety Score to organize area context.
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: 2026-08-31.
Frequently Asked Questions
What is EPA Radon Zone 1?
Zone 1 is the EPA highest county-level radon-potential category. It is not a measurement for a home and cannot determine whether a building is above an action level. A home test is required for that decision.
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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