Radon levels in Rhode Island: Low
The model predicts a population-weighted basement average of 1.6 pCi/L (model estimate) across Rhode Island's 5 counties - close to the US average of 1.8 pCi/L. Above-ground floors average 0.9 pCi/L.
Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. How the numbers work.
2 / 5
EPA Zone 1 counties (40%)
2 / 1
Zone 2 / Zone 3 counties
0
counties predicted ≥ 4 pCi/L
0%
of ZIP codes predicted ≥ 4 pCi/L
Test Rhode Island once anyway - radon varies house to house
The predicted basement average here is 1.6 pCi/L, below the EPA's 2 pCi/L "consider fixing" threshold. That's good news for the area - but the EPA still recommends every home be tested, because foundation cracks, soil pockets and ventilation make one house very different from its neighbor. One inexpensive kit settles it.
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What the data says about radon in Rhode Island
2 of Rhode Island's 5 counties are EPA Zone 1 (40%), 2 are Zone 2 and 1 is Zone 3 on the EPA's county-level map. Zone 1 - the highest-potential class, predicted screening average above 4 pCi/L - is the most common designation in Rhode Island. The zones were drawn once, from geology and the tests available in 1993, and the EPA itself notes that homes with elevated radon exist in all three zones.
Weighted by where people live, Rhode Island's predicted basement average is 1.6 pCi/L - close to the US average of 1.8 - which puts the state in the low range. Of the 5 counties with predictions, 0 are predicted at or above 4 pCi/L, 1 in the 2-4 band and 4 below 2. The highest predicted county is Washington County at 2.5 pCi/L; the lowest is Bristol County at 1.4 - a 1.1 pCi/L spread that means a statewide average tells you little about any one county.
Nationally 4.2% of ZIPs are predicted at 4+ pCi/L and 48.7% at 2+; in Rhode Island it is 0% and 40.3% - below the US share at the action level but near it at 2 pCi/L. No ZIP in the state is predicted above 4 on average - but averages hide individual homes, which is why the EPA still asks everyone to test.
Rhode Island counties by predicted radon
Sorted highest to lowest predicted basement average (model estimate). 5 counties.
| County | Predicted basement | Upstairs | Grade | EPA zone | ZIPs |
|---|---|---|---|---|---|
| Washington County | 2.5 pCi/L | 1.4 | Moderate | EPA Zone 1 | 19 |
| Newport County | 1.7 pCi/L | 1.2 | Low | EPA Zone 2 | 7 |
| Kent County | 1.7 pCi/L | 1.1 | Low | EPA Zone 1 | 8 |
| Providence County | 1.4 pCi/L | 0.8 | Low | EPA Zone 2 | 35 |
| Bristol County | 1.4 pCi/L | 0.7 | Low | EPA Zone 3 | 3 |
Radon levels in Rhode Island cities
The 5 most-populous Rhode Island places among the 1,000 largest US cities (Census incorporated places and CDPs), by population. City figures are ZIP-land-weighted means of the model's ZIP predictions (model estimate).
| City | Population | Predicted basement | Upstairs | Grade | ZIPs ≥ 4 |
|---|---|---|---|---|---|
| Providence | 190,792 | 1.1 pCi/L | 0.5 | Low | 0% |
| Warwick | 82,999 | 1.4 pCi/L | 0.8 | Low | 0% |
| Cranston | 82,635 | 1.5 pCi/L | 0.9 | Low | 0% |
| Pawtucket | 75,321 | 1.3 pCi/L | 0.6 | Low | 0% |
| East Providence | 46,900 | 1.1 pCi/L | 0.6 | Low | 0% |
Highest-radon ZIP codes in Rhode Island
The 10 Rhode Island ZIP codes with the highest predicted basement average (model estimate), out of 72 modeled. A ZIP average is still an area figure - neighboring homes routinely test several pCi/L apart.
| ZIP | County | Predicted basement | Upstairs | Grade |
|---|---|---|---|---|
| 02879 | Washington County | 3.3 pCi/L | 1.6 | Moderate |
| 02813 | Washington County | 3.1 pCi/L | 2.0 | Moderate |
| 02812 | Washington County | 3.0 pCi/L | 1.8 | Moderate |
| 02832 | Washington County | 2.7 pCi/L | 1.8 | Moderate |
| 02827 | Kent County | 2.7 pCi/L | 1.7 | Moderate |
| 02892 | Washington County | 2.6 pCi/L | 1.5 | Moderate |
| 02822 | Washington County | 2.6 pCi/L | 1.8 | Moderate |
| 02817 | Kent County | 2.6 pCi/L | 1.5 | Moderate |
| 02898 | Washington County | 2.6 pCi/L | 1.7 | Moderate |
| 02833 | Washington County | 2.6 pCi/L | 1.7 | Moderate |
Rhode Island radon questions
- Is radon high in Rhode Island?
- Rhode Island's population-weighted predicted basement average is 1.6 pCi/L, close to the US average of 1.8. 0 of its 5 modeled counties are predicted at or above the EPA action level of 4 pCi/L, 1 are in the 2-4 "consider fixing" range and 4 are below 2. 0% of Rhode Island ZIP codes are predicted at 4 or higher.
- Which Rhode Island county has the highest radon?
- Washington County has the highest predicted basement average in Rhode Island at 2.5 pCi/L (EPA Zone 1). The lowest is Bristol County at 1.4 pCi/L. These are area figures; individual homes in any county can test far higher.
- How many EPA Zone 1 counties are in Rhode Island?
- 2 of Rhode Island's 5 counties (40%) are EPA Zone 1 (highest potential), 2 are Zone 2 and 1 are Zone 3. The EPA zone map dates from 1993; the predicted values on this page come from a 2001-2021 model built on millions of actual tests, so the two can disagree for a given county.
- Should I test for radon in Rhode Island?
- Yes. Even though Rhode Island's predicted average is below 2 pCi/L, the EPA recommends every home be tested - radon varies house to house, and 40.3% of Rhode Island ZIP codes are still predicted at 2 pCi/L or higher.
Rhode Island radon program
Rhode Island's radon program page is at health.ri.gov; it lists testing and certified-mitigator guidance for the state. The EPA also keeps a directory of every state radon contact: EPA state radon contacts page. Then read how to test and what mitigation costs.