Rhode Island Cities Ranked by Indoor Radon Levels
Measured averages from Airthings devices across Rhode Island, USA. Action level: 4 pCi/L — the threshold at which remediation is recommended.
Charlestown has the highest measured indoor radon in Rhode Island at 5.7 pCi/L, based on Airthings measurements across 40 cities.
Updated September 28, 2026
Highest city
5.7pCi/L
Charlestown
Rhode Island city average
2.8pCi/L
across 40 cities
Above action level
7/ 40
cities
| # | Location | Avg level | vs action level |
|---|---|---|---|
| 1 | Charlestown | 5.7 pCi/L | 1.4× over |
| 2 | Hopkinton | 5.5 pCi/L | 1.4× over |
| 3 | West Greenwich | 5.1 pCi/L | 1.3× over |
| 4 | Hope Valley | 4.6 pCi/L | 1.1× over |
| 5 | Smithfield | 4.2 pCi/L | 1.0× over |
| 6 | Portsmouth | 4.1 pCi/L | 1.0× over |
| 7 | Kingston | 4.1 pCi/L | 1.0× over |
| ✓ Below EPA action level (4 pCi/L) | |||
| 8 | Bradford | 3.8 pCi/L | 0.9× under |
| 9 | North Scituate | 3.6 pCi/L | 0.9× under |
| 10 | West Warwick | 3.5 pCi/L | 0.9× under |
| 11 | East Greenwich | 3.3 pCi/L | 0.8× under |
| 12 | Tiverton | 3.2 pCi/L | 0.8× under |
| 13 | Newport | 3.1 pCi/L | 0.8× under |
| 14 | Central Falls | 3.0 pCi/L | 0.7× under |
| 15 | Exeter | 2.9 pCi/L | 0.7× under |
| 16 | Jamestown | 2.9 pCi/L | 0.7× under |
| 17 | Newport East | 2.9 pCi/L | 0.7× under |
| 18 | Pascoag | 2.8 pCi/L | 0.7× under |
| 19 | North Providence | 2.7 pCi/L | 0.7× under |
| 20 | Cumberland | 2.6 pCi/L | 0.7× under |
| 21 | North Kingstown | 2.6 pCi/L | 0.7× under |
| 22 | Westerly | 2.6 pCi/L | 0.6× under |
| 23 | Narragansett Pier | 2.6 pCi/L | 0.6× under |
| 24 | East Providence | 2.4 pCi/L | 0.6× under |
| 25 | Wakefield-Peacedale | 2.3 pCi/L | 0.6× under |
| 26 | Coventry | 2.2 pCi/L | 0.5× under |
| 27 | Greenville | 2.1 pCi/L | 0.5× under |
| 28 | North Smithfield | 2.0 pCi/L | 0.5× under |
| 29 | Barrington | 2.0 pCi/L | 0.5× under |
| 30 | Cranston | 2.0 pCi/L | 0.5× under |
| 31 | Pawtucket | 1.9 pCi/L | 0.5× under |
| 32 | Johnston | 1.9 pCi/L | 0.5× under |
| 33 | Cumberland Hill | 1.7 pCi/L | 0.4× under |
| 34 | Middletown | 1.7 pCi/L | 0.4× under |
| 35 | Warwick | 1.6 pCi/L | 0.4× under |
| 36 | Valley Falls | 1.6 pCi/L | 0.4× under |
| 37 | Chepachet | 1.5 pCi/L | 0.4× under |
| 38 | Providence | 1.3 pCi/L | 0.3× under |
| 39 | Woonsocket | 1.3 pCi/L | 0.3× under |
| 40 | Bristol | 1.1 pCi/L | 0.3× under |