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Radon Levels in Sitka City and Borough, Alaska

EPA puts Sitka City and Borough in Zone 3, its lowest radon zone, and only 3 radon tests from it are on file with CDC (2022). Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Nearest county

    3.1%

    Anchorage Municipality, 558 miles

    Anchorage Municipality
    3.1%
    Alaska
    11.5%

    Share at 4+ pCi/L, 130 tests, 2022

  • Ground above low

    None

    79.2 pts below Alaska

    Sitka City and Borough
    0.0%
    Alaska
    79.2%

    Share of land USGS rates moderate or high potential

  • Tests reported

    3

    Too few for a share

    Sitka City and Borough
    3
    Needed
    30

    2022

  • EPA radon zone

    Zone 3

    Lower potential

    1. 1
    2. 2
    3. Zone 3

    1 highest, 3 lowest

    EPA predicts under 2 pCi/L indoors

Read a result for Sitka City and Borough

Starts at EPA's action level

4.0pCi/L

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

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 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.

Interpret this readingWhat a fix costs

The data

Sitka City and Borough, At a glance

Sitka City and Borough at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Sitka City and Borough as a whole is an average indoor of less than 2 pCi/L (less than 75 Bq/m³). A low zone clears no address in it: homes above EPA's turn up in all three zones.

USGS geologic potential: Low across 87% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Sitka City and Borough, 2022

CDC holds 3 reported tests for Sitka City and Borough in 2022, with a median of 0.2 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Sitka City and Borough beside the counties around it is how this page reads it.

What these figures count

Only 3 tests were reported to CDC for Sitka City and Borough over 2022, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the borough or census area nor this house.

Measured: CDC tracking data. Figure above: 2022. Measured data period: 2005 to 2022 (every CDC figure on file).

How to read these figures

Sitka City and Borough, Compared

Sitka City and Borough radon figures, compared

Calculated by Radon411

CDC's largest figure for Sitka City and Borough rests on 3 tests in 2022, 0 of them at or above 4 pCi/L, so each test moves its share by 33.3 points and no rank or comparison is drawn from it. Results reached as high as 0.2 pCi/L, with a middle value of 0.2 pCi/L.

The nearest counties with a figure are Anchorage Municipality (558 miles away) at 3.1%, Matanuska-Susitna Borough (607 miles away) at 14.3% and Fairbanks North Star Borough (644 miles away) at 19.4%. Pooled across 19 Alaska counties, 11.5% of reported tests reached that level; across every county in the country with a figure, 23.9%.

Statewide for the same period, Fairbanks North Star Borough reported the highest share (19.4%) and Anchorage Municipality the lowest (3.1%). EPA's 1993 map puts Sitka City and Borough in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 87% of the county's land low radon potential.

Alaska, the United States and the counties around Sitka City and Borough, 2022
AreaTestsAt or above 4 pCi/LMedian
Alaska, pooled19 counties, pooled31411.5%Not pooled
United States, pooled853 counties, pooled333,14023.9%Not pooled
Fairbanks North Star Boroughhighest in the state7219.4%1.4 pCi/L
Anchorage Municipalitylowest in the state1303.1%0.5 pCi/L
Hoonah-Angoon Census Area, AKborders it10.0%0.4 pCi/L
Prince of Wales-Hyder Census Area, AKborders it10.0%0.4 pCi/L
The nearest Alaska counties to Sitka City and Borough with 30 or more tests, 2022
CountyDistanceTestsAt or above 4 pCi/LMedian
Anchorage Municipality558 mi1303.1%0.5 pCi/L
Matanuska-Susitna Borough607 mi4214.3%1.1 pCi/L
Fairbanks North Star Borough644 mi7219.4%1.4 pCi/L
Sitka City and Borough ten-year laboratory totals, against Alaska's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestAlaska, pooledChange from the row before
2008 to 201710.0%0.1 pCi/L0.1 pCi/L18.2%Level
2007 to 201610.0%0.1 pCi/L0.1 pCi/L20.0%Level
2006 to 201520.0%0.1 pCi/L0.1 pCi/L21.5%Level
2005 to 201430.0%0.1 pCi/L0.1 pCi/L22.5%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Sitka City and Borough, Geology

The ground under Sitka City and Borough

Predicted

USGS's geologic map puts all of Sitka City and Borough's mapped land in one class: low radon potential. 87.5% of it lies in the area the map calls Pacific Border Ranges, to which USGS gives a radon index of 7, in the low band (5 to 8).

USGS's geologic areas under Sitka City and Borough
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Pacific Border RangesPaleozoic and Mesozoic sedimentary and metamorphic rocks with some mafic volcanic and intrusive rocks.Low787.5%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Sitka City and Borough beside the ground around it

Across Alaska 79.2% of the land is rated moderate; none of Sitka City and Borough's is. Every one of the 2 boroughs and census areas that border it has more moderate-potential ground, Prince of Wales-Hyder Census Area the most at 84.9%.

Share of land by USGS radon potential: Sitka City and Borough, the 2 boroughs and census areas bordering it and Alaska
AreaEPA zoneLow potentialModerate potentialHigh potential
Sitka City and BoroughZone 387.5%NoneNone
Hoonah-Angoon Census AreaNot published63.3%29.7%None
Prince of Wales-Hyder Census AreaNot published0.1%84.9%None
Alaska29 boroughs and census areas, pooled by land areaVaries19.2%79.2%None

The map rates the ground, not the air in any home.

Local help

Sitka City and Borough, Local resources

Radon testing and mitigation in Sitka City and Borough

What Alaska's program says
Phone
907-269-6401
Email
paul.goodfellow@alaska.gov

What it means

Sitka City and Borough, Questions

Questions about radon in Sitka City and Borough

Are radon levels high in Sitka City and Borough?

In 2022, 0.0% of the radon tests reported to CDC for Sitka City and Borough, Alaska were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.2 pCi/L. Of the 3 nearest counties with a figure, within 644 miles, the share of tests at or above 4 pCi/L runs from 3.1% to 19.4%.

Which counties border Sitka City and Borough?

Sitka City and Borough borders 2 boroughs and census areas: Hoonah-Angoon Census Area and Prince of Wales-Hyder Census Area.

Products

Sitka City and Borough, Products

Testing a home in Sitka City and Borough

No CDC figure names Sitka City and Borough; the nearest county with one, Anchorage Municipality (558 miles away), reported 3.1% of its tests at or above 4 pCi/L in 2022, 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 Sitka City and Borough.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Sitka City and Borough homes, compared

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Sitka City and Borough, Bordering boroughs and census areas

Boroughs and census areas bordering Sitka City and Borough

Calculated by Radon411

Sitka City and Borough, Cities and towns

Cities and towns in Sitka City and Borough

About 8,319 people live in Sitka City and Borough by the Census Bureau's estimate for July 1, 2025, 111 fewer than in 2020 (−1.3%). Spread over its land, that is 2.9 people to the square mile. Sitka, its one incorporated place, has 8,319 residents, 100.0% of the total. CDC's 3 reported tests for 2022 work out to 0.4 per 1,000 residents (2025 estimate), close to Alaska's 0.4.

Sitka is the one incorporated place here; CDC publishes no figure by town, so it reads Sitka City and Borough's.

Sitka, Sitka City and Borough: residents on July 1, 2025
PlaceResidentsSince 2020Share of residents
Sitka8,319−1.3%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).

Sitka City and Borough, Homes

Homes in Sitka City and Borough

Fewer than six in ten of Sitka City and Borough's 4,167 homes are detached houses (51%, against 63% across Alaska); the rest are attached, in shared buildings or mobile. Half of its homes were built before 1979, close to Alaska's 1985: 15% date from before 1960 and 15% from 2000 or later. 62% of occupied homes are lived in by their owner (Alaska: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Sitka City and Borough, Alaska, 2019 to 2023
HomesSitka City and BoroughAlaska
Housing units4,167327,610
Detached houses51%63%
In buildings of 5 or more11%12%
Mobile homes8%4%
Built before 196015%8%
Built since 200015%25%
Middle year built19791985
Owner-occupied62%67%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.