Minnesota · county radon data
Radon in Ramsey County, Minnesota
30.5% of the 6,744 home radon tests on record here reached the EPA action level — toward the lower end of the state's tested counties, ranked #76 of 87 tested Minnesota counties.
What the numbers say
Ramsey County sits 25.4 points below the Minnesota median (55.9% of tests over the limit across the state's counties). The median reading among its 6,744 reported tests was 2.7 pCi/L — and the single highest test on record reached 188.1 pCi/L, more than 47× the action level. EPA maps place the county in Radon Zone 1 — its highest-potential category, where average indoor screening levels are predicted above 4 pCi/L.
Why: the ground under Ramsey County
Blanketed by clay-rich glacial till carrying ground-up uranium-bearing rock — the geologic reason nearly all of Minnesota is EPA Zone 1 and the state's average indoor radon runs roughly triple the national average. Long heating seasons in tight houses compound what the ground supplies.
Geology sources: MN Dept of Health · USGS WRI 98-4169.
The housing stock factor
The median Ramsey County home dates to 1965 — decades before radon-resistant new construction entered building codes. With 542,945 residents largely housed in that older stock, testing is the only way any individual household knows where it stands.
ZIP codes in Ramsey County
Minnesota doesn't publish ZIP-level test results, so these ZIPs share the county figures above — the roster is here so you can confirm your address is covered by this data.
| ZIP | Place |
|---|---|
| 55101 | Saint Paul |
| 55102 | Saint Paul |
| 55103 | Saint Paul |
| 55104 | Saint Paul |
| 55105 | Saint Paul |
| 55106 | Saint Paul |
| 55107 | Saint Paul |
| 55108 | Saint Paul |
| 55109 | Saint Paul |
| 55110 | Saint Paul |
| 55112 | Saint Paul |
| 55113 | Saint Paul |
| 55114 | Saint Paul |
| 55116 | Saint Paul |
| 55117 | Saint Paul |
| 55119 | Saint Paul |
| 55126 | Saint Paul |
| 55127 | Saint Paul |
| 55130 | Saint Paul |
| 55155 | Saint Paul |
Ramsey County in the Minnesota picture
| Ramsey County | 30.5% over the limit | 6,744 tests |
| Minnesota's highest: Rock County | 83.8% | 138 tests |
| Minnesota county median | 55.9% | 87 counties ranked |
| Share of all Minnesota tests from this county | 7.4% | |
Ranked nearby in Minnesota
- Washington County — #73, 31.5% of 4,469 tests over the limit
- Benton County — #74, 30.7% of 348 tests over the limit
- Aitkin County — #75, 30.5% of 166 tests over the limit
- Kittson County — #77, 30.4% of 15 tests over the limit
- Roseau County — #78, 29.2% of 36 tests over the limit
- Crow Wing County — #79, 27.9% of 816 tests over the limit
(Ranking neighbors — counties adjacent in the Minnesota test ranking, not necessarily on the map.)
High test? Fixes and real pricing: the Minnesota mitigation cost guide. Every statistic here traces to the methodology (CDC EPHT (labs), 2008–2017; zones: EPA; year built & population: ACS 5-year).
Ramsey County radon FAQ
- Is radon high in Ramsey County?
- 30.5% of 6,744 home tests reported to the CDC came back at or above the EPA action level of 4 pCi/L — 25.4 points below the Minnesota county median of 55.9%, ranking #76 of 87 tested counties. EPA classifies the county as Zone 1.
- Does an older home in Ramsey County mean more radon risk?
- The county's median home was built in 1965 — before radon-resistant construction practices entered building codes in the 1990s, so most of the housing stock has no built-in radon protection. Construction age changes the odds, not the answer: only a test tells you about your house.
- Where do these Ramsey County numbers come from?
- 6,744 aggregated home tests in the CDC's Environmental Public Health Tracking dataset (CDC EPHT 2008-2017). Median reading: 2.7 pCi/L; the highest recorded test hit 188.1 pCi/L. How we handle the data, including its limits, is documented on our methodology page.
- What's the highest radon reading recorded in Ramsey County?
- 188.1 pCi/L — 47× the EPA action level — against a county median of 2.7 pCi/L across 6,744 tests. That spread is the point: neighboring homes routinely test wildly differently.