Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
Radon Levels in Williamsburg city, Virginia
EPA puts Williamsburg city in Zone 3, its lowest radon zone, and only 19 radon tests from it are on file with CDC (2008 to 2017, laboratory totals). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Highest bordering
38.4%
James City County
- James City
- 38.4%
1 of 2 neighbours have 30+ tests, 2006 to 2015
Nearest county
38.4%
James City County, 6 miles
- James City
- 38.4%
- Virginia
- 30.7%
Share at 4+ pCi/L, 73 tests, 2006 to 2015
Ground above low
None
77.9 pts below Virginia
- Williamsburg city
- 0.0%
- Virginia
- 77.9%
Share of land USGS rates moderate or high potential
Tests reported
19
Too few for a share
- Williamsburg city
- 19
- Needed
- 30
2008 to 2017, laboratory
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 Williamsburg city
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
Williamsburg city, At a glance
Williamsburg city at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Williamsburg city, 2008 to 2017, laboratory
CDC holds 19 reported tests for Williamsburg city over the 2008 to 2017 laboratory totals, with a median of 0.8 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Williamsburg city beside the counties around it is how this page reads it.
What these figures count
Only 19 tests were reported to CDC for Williamsburg city over 2008 to 2017 (laboratory totals), and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Williamsburg city, Compared
Williamsburg city radon figures, compared
Calculated by Radon411CDC's largest figure for Williamsburg city rests on 19 tests over the 2008 to 2017 laboratory totals, 2 of them at or above 4 pCi/L, so each test moves its share by 5.3 points and no rank or comparison is drawn from it. Results reached as high as 17.8 pCi/L, with a middle value of 0.8 pCi/L.
James City County, the one bordering county with a figure over the 2006 to 2015 laboratory totals, reported 38.4% of its tests at or above 4 pCi/L. Farther out, Newport News city (15 miles away) at 5.9%, Norfolk city (36 miles away) at 5.3% and Henrico County (43 miles away) at 25.7% have figures too. Pooled across 132 Virginia counties, 30.7% of reported tests reached that level; across every county in the country with a figure, 36.3%.
Statewide for the same period, Russell County reported the highest share (68.5%) and Norfolk city the lowest (5.3%). EPA's 1993 map puts Williamsburg city in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 100% of the county's land low radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Williamsburg city, Geology
The ground under Williamsburg city
PredictedUSGS's geologic map puts all of Williamsburg city's mapped land in one class: low radon potential. All of it lies in the area the map calls Tertiary Coastal Plain Sediments, to which USGS gives a radon index of 8, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Tertiary Coastal Plain Sediments | Tertiary Coastal Plain sand, silt, clay | Low | 8 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Williamsburg city beside the ground around it
Across Virginia 47.9% of the land is rated high; none of Williamsburg city's is. None of the 2 counties that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Williamsburg city, Local resources
Radon testing and mitigation in Williamsburg city
- VDH Radon ProgramVDH Radon Program answers questions about testing, mitigation and the rules in Virginia.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
- Professionals in Virginia2 professionals are listed in Virginia.
What Virginia's program says
- Phone
- (804) 864-8161
- Radon@vdh.virginia.gov
- Licensing of radon professionals
The Code of Virginia requires that Radon testers and mitigators be currently certified by either the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB).
What it means
Williamsburg city, Questions
Questions about radon in Williamsburg city
Are radon levels high in Williamsburg city?
Over the 2008 to 2017 laboratory totals, 10.5% of the radon tests reported to CDC for Williamsburg city, Virginia were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.8 pCi/L. James City County, the one bordering county with a figure over the 2006 to 2015 laboratory totals, reported 38.4% of its tests at or above 4 pCi/L.
Which counties border Williamsburg city?
Williamsburg city borders 2 counties: James City County and York County.
Products
Williamsburg city, Products
Testing a home in Williamsburg city
No CDC figure names Williamsburg city; the nearest county with one, James City County (6 miles away), reported 38.4% of its tests at or above 4 pCi/L over the 2006 to 2015 laboratory totals, the only reading nearby until a test of this home. 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 Williamsburg city.
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
RM-63Pro rechargeable radon monitor with a touchscreen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Williamsburg city, Bordering counties
Counties bordering Williamsburg city
Calculated by Radon411- Radon levels in James City CountyEPA zone 3
38.4%at or above 4 pCi/L
Median 2.4 pCi/L · 73 tests
- Radon levels in York CountyEPA zone 3
18.2%at or above 4 pCi/L
Median 1.2 pCi/L · 22 tests
Williamsburg city, Cities and towns
Cities and towns in Williamsburg city
The Census Bureau estimates 15,861 residents in Williamsburg city for July 1, 2025, 402 more than in 2020 (+2.6%). Packed into its land, that is 1,775 people per square mile. Williamsburg, its one incorporated place, has 15,861 residents, 100.0% of the total. Reported testing is thin here: 19 tests over 2008 to 2017, or 1.2 for every 1,000 residents (2025 estimate), where Virginia as a whole comes to 6.0.
Williamsburg is the one incorporated place here; CDC publishes no figure by town, so it reads Williamsburg city's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Williamsburg | 15,861 | +2.6% | 100.0% |
One incorporated place, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Williamsburg city, Homes
Homes in Williamsburg city
Williamsburg city has 5,767 homes, and many share a building: 31% are in buildings of five or more, 40% are detached houses, against 61% across Virginia. Half of its homes were built before 1987, close to Virginia's 1984: 15% date from before 1960 and 33% from 2000 or later. 53% of occupied homes are lived in by their owner (Virginia: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Williamsburg city | Virginia |
|---|---|---|
| Housing units | 5,767 | 3,654,784 |
| Detached houses | 40% | 61% |
| In buildings of 5 or more | 31% | 19% |
| Mobile homes | under 1% | 4% |
| Built before 1960 | 15% | 19% |
| Built since 2000 | 33% | 25% |
| Middle year built | 1987 | 1984 |
| Owner-occupied | 53% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.