North Dakota Radon Map, Levels & Testing Guide
Browse the 53 listed county pages surfaced for North Dakota. Open a listed county to compare its EPA zone, source caveats, testing meaning, and when mitigation pricing becomes worth checking.
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Official Evidence in North Dakota
53 of 53 listed counties have official evidence
Open a county page to see the official source context: measurement fields, local burden, state percentile, and the next step for no reading, 2.0-3.9, or 4.0+ pCi/L.
100%
covered
Measured
53
State source
0
CDC source
53
Needs source detail
0
Measured Risk Leaders in North Dakota
County rankings from actual reported radon tests
These lists rank the visible North Dakota county pages by measured radon signals, not by the EPA zone label alone. Use them to spot where the state hub has a real data story before opening individual county pages.
53
measured counties
State-level evidence read
This hub has measured high-burden counties, so the first click should be evidence-led.
The state hub is now doing a decision job: it separates first-click counties, retest counties, and lower-signal counties from 53 visible county measurement rows. 50 counties cross the high measured-burden band, so those pages should answer testing and 4.0+ action questions most directly.
First-click counties
Open Billings County first when you need the strongest local answer. It is tagged Test-now from 85.0% 4.0+ - 16.4 pCi/L primary - 12 tests. 51 visible measured counties are elevated or high enough to review before lower-signal counties.
Buyer/seller lane
Buyer/seller lane: start with the elevated or high counties, require a fresh lowest-level test, and turn any 4.0+ property result into quote or credit math. The hub has 53 CDC-backed county rows to support that routing.
Retest lane
Retest lane: 2.0-3.9 pCi/L deserves more caution in the elevated/high county set than in lower-signal counties. The hub should send those users to county pages before product or cost paths.
Best county pages to open first
Start with these local evidence pages
Ranked by measured burden, 4.0+ share, test volume, and whether the EPA zone understates the measurement signal.
Billings County
CDC Tracking
85.0% 4.0+ - 16.4 pCi/L primary - 12 tests
Billings County is a first-click page: 85.0% of reported tests at or above 4.0 and 16.4 pCi/L primary result. Route no-reading users to a test now and 4.0+ users to quote or credit planning.
Pembina County
CDC Tracking
82.5% 4.0+ - 13.8 pCi/L primary - 41 tests
Pembina County is a first-click page: 82.5% of reported tests at or above 4.0 and 13.8 pCi/L primary result. Route no-reading users to a test now and 4.0+ users to quote or credit planning.
Walsh County
CDC Tracking
79.5% 4.0+ - 13.2 pCi/L primary - 89 tests
Walsh County is a first-click page: 79.5% of reported tests at or above 4.0 and 13.2 pCi/L primary result. Route no-reading users to a test now and 4.0+ users to quote or credit planning.
Sioux County
CDC Tracking
100.0% 4.0+ - 9.3 pCi/L primary - 2 tests
Sioux County is a first-click page: 100.0% of reported tests at or above 4.0 and 9.3 pCi/L primary result. Route no-reading users to a test now and 4.0+ users to quote or credit planning.
Highest 4.0+ share
Primary result 9.3 pCi/L - high-end 11.7 pCi/L
CDC Tracking
Primary result 9.9 pCi/L - high-end 40.9 pCi/L
CDC Tracking
Primary result 16.4 pCi/L - high-end 93.9 pCi/L
CDC Tracking
Primary result 13.8 pCi/L - high-end 62.9 pCi/L
CDC Tracking
Primary result 11.1 pCi/L - high-end 22.1 pCi/L
CDC Tracking
Highest high-end reading
4.0+ share 75.9% - primary result 10.7 pCi/L
CDC Tracking
4.0+ share 53.4% - primary result 6.5 pCi/L
CDC Tracking
4.0+ share 57.5% - primary result 7.1 pCi/L
CDC Tracking
4.0+ share 61.6% - primary result 11.1 pCi/L
CDC Tracking
4.0+ share 79.5% - primary result 13.2 pCi/L
CDC Tracking
Most reported tests
4.0+ share 51.1% - primary result 5.1 pCi/L
CDC Tracking
4.0+ share 57.5% - primary result 7.1 pCi/L
CDC Tracking
4.0+ share 75.9% - primary result 10.7 pCi/L
CDC Tracking
4.0+ share 43.0% - primary result 4.3 pCi/L
CDC Tracking
4.0+ share 73.5% - primary result 7.5 pCi/L
CDC Tracking
Measured pattern
Among 53 visible counties with measurement tables, 50 land in the high measured-burden band and 51 land in high or elevated measured-burden bands. That lets this hub rank counties by observed test distribution instead of repeating the EPA map.
Map vs measurements
The strongest measured signals mostly align with the EPA zone structure, so the county pages can use the map as support while still leading with test data.
Source strategy
The measured rows shown here use CDC Tracking. This is still official evidence, but the hub should keep source caveats visible until a stable state table is available.
Already Tested
View North Dakota Cost Estimates
If you already have a radon result, skip the directory and move straight to local price guidance.
Understand the Number
2.0 vs 4.0 vs 8.0 pCi/L
Use the parent levels guide if you need the plain-English meaning of a radon result before browsing counties.
Need a Number First
Read the Testing Guide
Use the fastest valid radon test setup before you compare quotes or ask whether mitigation is worth it.
Browse Counties
Jump to the Directory
Open your county to see its EPA zone, testing meaning, and the point where mitigation becomes worth pricing.
Official State Resource
North Dakota radon program and rules
Use the state program link to verify local radon guidance, disclosure language, and contractor credential expectations before you act on an estimate.
Disclosure rule tracked
North Dakota requires sellers to complete a Seller's Property Condition Disclosure Statement.
Credential note
North Dakota does not require specific radon licensing.
Already tested? Get your itemized mitigation cost estimate.
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