Out of 133 ZIP codes with data in Washington, these are the lowest-ranked areas for radon zone. See also: National ZIP Codes in EPA Radon Zone 1 | All Washington Rankings
| Statistic | Value |
|---|---|
| ZIP codes ranked | 133 |
| Lowest value | Zone 1 (highest potential) |
| Median value | Zone 1 (highest potential) |
| State | Washington |
100 Lowest-Ranked ZIP Codes
| Rank | ZIP Code | City | State | Radon Zone | Safety Score |
|---|---|---|---|---|---|
| 1 | 99003 | Chattaroy | WA | Zone 1 (highest potential) | 36/100 |
| 2 | 99006 | Deer Park | WA | Zone 1 (highest potential) | 36/100 |
| 3 | 99216 | Spokane | WA | Zone 1 (highest potential) | 42/100 |
| 4 | 99217 | Spokane | WA | Zone 1 (highest potential) | 42/100 |
| 5 | 98683 | Vancouver | WA | Zone 1 (highest potential) | 46/100 |
| 6 | 99223 | Spokane | WA | Zone 1 (highest potential) | 46/100 |
| 7 | 98607 | Camas | WA | Zone 1 (highest potential) | 47/100 |
| 8 | 99021 | Mead | WA | Zone 1 (highest potential) | 47/100 |
| 9 | 99208 | Spokane | WA | Zone 1 (highest potential) | 47/100 |
| 10 | 99212 | Spokane | WA | Zone 1 (highest potential) | 47/100 |
| 11 | 99224 | Spokane | WA | Zone 1 (highest potential) | 47/100 |
| 12 | 98604 | Battle Ground | WA | Zone 1 (highest potential) | 48/100 |
| 13 | 98682 | Vancouver | WA | Zone 1 (highest potential) | 48/100 |
| 14 | 98684 | Vancouver | WA | Zone 1 (highest potential) | 48/100 |
| 15 | 99005 | Colbert | WA | Zone 1 (highest potential) | 48/100 |
| 16 | 99022 | Medical Lake | WA | Zone 1 (highest potential) | 48/100 |
| 17 | 98601 | Amboy | WA | Zone 1 (highest potential) | 49/100 |
| 18 | 98642 | Ridgefield | WA | Zone 1 (highest potential) | 49/100 |
| 19 | 98675 | Yacolt | WA | Zone 1 (highest potential) | 49/100 |
| 20 | 99004 | Cheney | WA | Zone 1 (highest potential) | 49/100 |
| 21 | 99026 | Nine Mile Falls | WA | Zone 1 (highest potential) | 49/100 |
| 22 | 99205 | Spokane | WA | Zone 1 (highest potential) | 49/100 |
| 23 | 99218 | Spokane | WA | Zone 1 (highest potential) | 49/100 |
| 24 | 98606 | Brush Prairie | WA | Zone 1 (highest potential) | 50/100 |
| 25 | 98629 | La Center | WA | Zone 1 (highest potential) | 50/100 |
| 26 | 98660 | Vancouver | WA | Zone 1 (highest potential) | 50/100 |
| 27 | 98661 | Vancouver | WA | Zone 1 (highest potential) | 50/100 |
| 28 | 98662 | Vancouver | WA | Zone 1 (highest potential) | 50/100 |
| 29 | 98663 | Vancouver | WA | Zone 1 (highest potential) | 50/100 |
| 30 | 98664 | Vancouver | WA | Zone 1 (highest potential) | 50/100 |
| 31 | 98665 | Vancouver | WA | Zone 1 (highest potential) | 50/100 |
| 32 | 98685 | Vancouver | WA | Zone 1 (highest potential) | 50/100 |
| 33 | 98686 | Vancouver | WA | Zone 1 (highest potential) | 50/100 |
| 34 | 99001 | Airway Heights | WA | Zone 1 (highest potential) | 50/100 |
| 35 | 99011 | Fairchild Air Force Base | WA | Zone 1 (highest potential) | 50/100 |
| 36 | 99201 | Spokane | WA | Zone 1 (highest potential) | 50/100 |
| 37 | 99202 | Spokane | WA | Zone 1 (highest potential) | 50/100 |
| 38 | 99203 | Spokane | WA | Zone 1 (highest potential) | 50/100 |
| 39 | 99204 | Spokane | WA | Zone 1 (highest potential) | 50/100 |
| 40 | 99207 | Spokane | WA | Zone 1 (highest potential) | 50/100 |
| 41 | 99258 | Spokane | WA | Zone 1 (highest potential) | 50/100 |
| 42 | 99206 | Spokane | WA | Zone 1 (highest potential) | 59/100 |
| 43 | 99016 | Greenacres | WA | Zone 1 (highest potential) | 61/100 |
| 44 | 99037 | Veradale | WA | Zone 1 (highest potential) | 61/100 |
| 45 | 99019 | Liberty Lake | WA | Zone 1 (highest potential) | 63/100 |
| 46 | 99114 | Colville | WA | Zone 1 (highest potential) | 63/100 |
| 47 | 98841 | Omak | WA | Zone 1 (highest potential) | 67/100 |
| 48 | 98603 | Ariel | WA | Zone 1 (highest potential) | — |
| 49 | 98605 | Bingen | WA | Zone 1 (highest potential) | — |
| 50 | 98610 | Carson | WA | Zone 1 (highest potential) | — |
| 51 | 98616 | Cougar | WA | Zone 1 (highest potential) | — |
| 52 | 98622 | Heisson | WA | Zone 1 (highest potential) | — |
| 53 | 98639 | North Bonneville | WA | Zone 1 (highest potential) | — |
| 54 | 98648 | Stevenson | WA | Zone 1 (highest potential) | — |
| 55 | 98666 | Vancouver | WA | Zone 1 (highest potential) | — |
| 56 | 98668 | Vancouver | WA | Zone 1 (highest potential) | — |
| 57 | 98671 | Washougal | WA | Zone 1 (highest potential) | — |
| 58 | 98687 | Vancouver | WA | Zone 1 (highest potential) | — |
| 59 | 98812 | Brewster | WA | Zone 1 (highest potential) | — |
| 60 | 98814 | Carlton | WA | Zone 1 (highest potential) | — |
| 61 | 98819 | Conconully | WA | Zone 1 (highest potential) | — |
| 62 | 98827 | Loomis | WA | Zone 1 (highest potential) | — |
| 63 | 98829 | Malott | WA | Zone 1 (highest potential) | — |
| 64 | 98833 | Mazama | WA | Zone 1 (highest potential) | — |
| 65 | 98834 | Methow | WA | Zone 1 (highest potential) | — |
| 66 | 98840 | Okanogan | WA | Zone 1 (highest potential) | — |
| 67 | 98844 | Oroville | WA | Zone 1 (highest potential) | — |
| 68 | 98846 | Pateros | WA | Zone 1 (highest potential) | — |
| 69 | 98849 | Riverside | WA | Zone 1 (highest potential) | — |
| 70 | 98852 | Stehekin | WA | Zone 1 (highest potential) | — |
| 71 | 98855 | Tonasket | WA | Zone 1 (highest potential) | — |
| 72 | 98856 | Twisp | WA | Zone 1 (highest potential) | — |
| 73 | 98859 | Wauconda | WA | Zone 1 (highest potential) | — |
| 74 | 98862 | Winthrop | WA | Zone 1 (highest potential) | — |
| 75 | 99009 | Elk | WA | Zone 1 (highest potential) | — |
| 76 | 99013 | Ford | WA | Zone 1 (highest potential) | — |
| 77 | 99014 | Four Lakes | WA | Zone 1 (highest potential) | — |
| 78 | 99020 | Marshall | WA | Zone 1 (highest potential) | — |
| 79 | 99023 | Mica | WA | Zone 1 (highest potential) | — |
| 80 | 99025 | Newman Lake | WA | Zone 1 (highest potential) | — |
| 81 | 99027 | Otis Orchards | WA | Zone 1 (highest potential) | — |
| 82 | 99030 | Rockford | WA | Zone 1 (highest potential) | — |
| 83 | 99031 | Spangle | WA | Zone 1 (highest potential) | — |
| 84 | 99034 | Tumtum | WA | Zone 1 (highest potential) | — |
| 85 | 99036 | Valleyford | WA | Zone 1 (highest potential) | — |
| 86 | 99039 | Waverly | WA | Zone 1 (highest potential) | — |
| 87 | 99040 | Wellpinit | WA | Zone 1 (highest potential) | — |
| 88 | 99101 | Addy | WA | Zone 1 (highest potential) | — |
| 89 | 99107 | Boyds | WA | Zone 1 (highest potential) | — |
| 90 | 99109 | Chewelah | WA | Zone 1 (highest potential) | — |
| 91 | 99110 | Clayton | WA | Zone 1 (highest potential) | — |
| 92 | 99116 | Coulee Dam | WA | Zone 1 (highest potential) | — |
| 93 | 99118 | Curlew | WA | Zone 1 (highest potential) | — |
| 94 | 99119 | Cusick | WA | Zone 1 (highest potential) | — |
| 95 | 99121 | Danville | WA | Zone 1 (highest potential) | — |
| 96 | 99124 | Elmer City | WA | Zone 1 (highest potential) | — |
| 97 | 99126 | Evans | WA | Zone 1 (highest potential) | — |
| 98 | 99129 | Fruitland | WA | Zone 1 (highest potential) | — |
| 99 | 99131 | Gifford | WA | Zone 1 (highest potential) | — |
| 100 | 99137 | Hunters | WA | Zone 1 (highest potential) | — |
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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