Short-term kit
Radon Short Term Test Kit short-term charcoal radon test kit, lab fee included
- Lab fee included
Method: Charcoal
In home: 2 to 7 days
Locations and reports
Radon Levels in Kauai County, Hawaii
EPA puts Kauai County in Zone 3, its lowest radon zone. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Ground above low
None
Level with Hawaii
- Kauai
- 0.0%
- Hawaii
- 0.0%
Share of land USGS rates moderate or high potential
Tests reported
0
None published
A home here needs its own test
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Kauai County
Starts at EPA's action level
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher.
The data
Kauai County, At a glance
Kauai County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 96% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
No CDC test figures here
CDC has published no radon test figures for Kauai County. Only a test tells you the level in a home.
Kauai County, Compared
Kauai County radon figures, compared
Calculated by Radon411CDC publishes no radon test figure for Kauai County, and none for any other Hawaii county: its counts over the 2006 to 2015 laboratory totals cover 2,669 counties elsewhere in the country. Across every county in the country with a figure (2,669), 36.3% of reported tests reached that level; no Hawaii county contributes to that pool.
EPA's 1993 map puts Kauai County in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 96% of the county's land low radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Kauai County, Geology
The ground under Kauai County
PredictedUSGS's geologic map puts all of Kauai County's mapped land in one class: low radon potential. The map puts 86.1% of Kauai County in the area it calls Kauai and 9.6% in Niihau. USGS gives both a radon index of 5, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Kauai | Primarily alkalic and tholeiitic basalt, colluvium and alluvium derived from basalt, lesser amounts of marine sediments and carbonate rocks | Low | 5 | 86.1% |
| Niihau | Primarily alkalic and tholeiitic basalt, colluvium and alluvium derived from basalt, lesser amounts of marine sediments and carbonate rocks | Low | 5 | 9.6% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Kauai County beside the ground around it
Neither Kauai County nor Hawaii as a whole has any land USGS rates above low potential.
The map rates the ground, not the air in any home.
Local help
Kauai County, Local resources
Radon testing and mitigation in Kauai County
- Hawaii's radon programHawaii's radon program answers questions about testing, mitigation and the rules where you live.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- See the Hawaii directoryNo professionals are listed in Hawaii yet. The state program can point you to registered testers and mitigators.
What it means
Kauai County, Questions
Questions about radon in Kauai County
Are radon levels high in Kauai County?
No CDC testing statistics are published here for Kauai County, Hawaii yet. No county within 250 miles of Kauai County has a CDC figure, so the only comparison is the national pool: 36.3% of reported tests at or above 4 pCi/L.
Which counties border Kauai County?
No county is recorded as sharing a land boundary with Kauai County.
Products
Kauai County, Products
Testing a home in Kauai County
No CDC figure names Kauai County, and none within 250 miles of it: a test of this home is the only reading it will get. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Kauai County.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Monitor
EcoBlu plug-in digital radon monitor with a display
- C-NRPP 2024/25: Not included
- Plug-in
- Alarm
- Screen
Method: Ion chamber
First reading: Within 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Kauai County, Bordering counties
Counties bordering Kauai County
Calculated by Radon411No bordering counties on file
Kauai County has no county recorded as sharing a land boundary with it. Island and coastal county equivalents legitimately have none.
Kauai County, Residents
Who lives in Kauai County
Kauai County's population has barely moved since 2020: 73,400 residents on July 1, 2025 against 73,210 then, by the Census Bureau's estimates. That works out to 118 people per square mile of land.
Census lists no incorporated place in Kauai County: every home in it reads the county's figures.
Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Kauai County, Homes
Homes in Kauai County
Of Kauai County's 30,392 homes, 69% are detached houses, against 54% across Hawaii; 18% are in buildings of five or more homes. Half of its homes were built before 1983, close to Hawaii's 1979: 14% date from before 1960 and 19% from 2000 or later. 67% of occupied homes are lived in by their owner (Hawaii: 63%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Kauai County | Hawaii |
|---|---|---|
| Housing units | 30,392 | 564,905 |
| Detached houses | 69% | 54% |
| In buildings of 5 or more | 18% | 31% |
| Mobile homes | under 1% | under 1% |
| Built before 1960 | 14% | 15% |
| Built since 2000 | 19% | 20% |
| Middle year built | 1983 | 1979 |
| Owner-occupied | 67% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.