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Radon Levels in Fillmore County, Nebraska

EPA puts Fillmore County in Zone 1, its highest radon zone, and only 9 radon tests from it are on file with CDC (2023). 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

  • Share at 4+ pCi/L

    61.2%

    13.8 pts above NE

    Fillmore
    61.2%
    Nebraska
    47.4%

    201 tests, 2016

  • Median result

    6.2pCi/L

    Action level reached

    Fillmore
    6.2 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2016

  • Tests reported

    201

    39th of 71 by tests

    Fillmore
    201
    Douglas
    20,817

    Reported to CDC before any fix, 2016

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in Nebraska

    22 of 71

    Middle half

    Fillmore
    61.2%
    Dixon
    85.5%

    By share, of 71 with 30+ tests

Read a result for Fillmore County

Starts at Fillmore County's median, 6.2 pCi/L

6.2pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 6.2 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. Fillmore County's median reported result, 2016.

Interpret this readingWhat a fix costs

The data

Fillmore County, At a glance

Fillmore County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Fillmore County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

USGS geologic potential: High across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Fillmore County, 2023

Share of reported tests at or above 4 pCi/L, by year, Fillmore County
Share of reported tests at or above 4 pCi/L, by year, Fillmore County
YearShare of reported tests at or above 4 pCi/L
201470.0%
201571.4%
201661.2%
201763.6%
201864.7%
201973.0%
202065.4%
202143.3%
202261.1%
2023100.0%

2023: 100.0%. Across these years the share ran from 43.3% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 9 tests were reported to CDC for Fillmore County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

How to read these figures

Fillmore County, Compared

Fillmore County radon figures, compared

Calculated by Radon411

More than half: 61.2% of the 201 radon tests reported to CDC for Fillmore County in 2016 read at least 4 pCi/L. That places it 22nd of 71 Nebraska counties with 30 or more tests for the same period. That is 13.8 points above the 47.4% pooled from 89 Nebraska counties.

The newest figure, in 2023, counts only 9 tests (100.0% at or above 4 pCi/L), too few to compare, so this reading uses the 201-test figure.

The median result, 6.2 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 23.5 pCi/L. The rest split 17.9% under 2 pCi/L and 20.9% from 2 to 4 (Nebraska: 24.9% and 27.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 61.2% share point the same way here.

4 of its 8 bordering counties with figures ran higher, led by Clay County at 79.6%; Jefferson County reported 50.0%. Statewide for the same period, Dixon County reported the highest share (85.5%) and Sheridan County the lowest (20.0%).

The busiest year on file was 2016, with 201 tests reported; the quietest, 2023, had 9.

Over 9 years of annual figures the share fell 8.9 points, from 70.0% in 2014 to 61.1% in 2022; its peak was 73.0% in 2019. Nationally, every county with a figure for the same period pools to 31.2%; Fillmore County sits 30.0 points above it.

Share of reported tests at or above 4 pCi/L by year, Fillmore County against Nebraska2014 to 2022, years with 30 or more tests: Fillmore County 70.0% to 61.1%, the state's pooled share 34.0% in 2022.
Fillmore CountyNebraska, pooled
Share of reported tests at or above 4 pCi/L by year, Fillmore County against Nebraska: data table
YearTestsFillmore County, at or above 4 pCi/LNebraska, pooled
20149070.0%50.5%
201514771.4%53.3%
201620161.2%47.4%
201713263.6%47.7%
201815364.7%44.5%
201911173.0%44.3%
20207865.4%42.2%
202118043.3%34.9%
20223661.1%34.0%
Fillmore County against Nebraska, the United States and nearby counties, 2016
AreaTestsAt or above 4 pCi/LMedianDifference from Fillmore County
Fillmore County20161.2%6.2 pCi/LThis county
Nebraska, pooled89 counties, pooled67,49147.4%Not pooled−13.8 points
United States, pooled886 counties, pooled398,20731.2%Not pooled−30.0 points
Dixon Countyhighest in the state20785.5%7.1 pCi/L+24.3 points
Sheridan Countylowest in the state4520.0%2.3 pCi/L−41.2 points
Clay County, NEborders it14779.6%7.9 pCi/L+18.4 points
Hamilton County, NEborders it34572.2%6.1 pCi/L+11.0 points
York County, NEborders it94868.7%6.8 pCi/L+7.5 points
Nuckolls County, NEborders it16864.3%5.7 pCi/L+3.1 points
Seward County, NEborders it67560.0%5.2 pCi/L−1.2 points
Saline County, NEborders it28858.3%5.0 pCi/L−2.9 points
Thayer County, NEborders it12652.4%4.6 pCi/L−8.8 points
Jefferson County, NEborders it21050.0%3.9 pCi/L−11.2 points
Where Fillmore County's reported results fell, 2016, beside Nebraska and the United States
ResultFillmore County testsFillmore County shareNebraska shareU.S. shareAgainst Nebraska
Under 2 pCi/L3617.9%24.9%44.8%−7.0 points
2 to 4 pCi/L4220.9%27.7%24.0%−6.8 points
4 pCi/L and above12361.2%47.4%31.2%+13.8 points
Fillmore County ranked among the 71 Nebraska counties with 30 or more tests, by share at or above 4 pCi/L, 2016
CountyRankTestsAt or above 4 pCi/LMedian
Nemaha County17 of 7125565.9%5.4 pCi/L
Kearney County18 of 7117465.5%4.8 pCi/L
Nuckolls County19 of 7116864.3%5.7 pCi/L
Saunders County20 of 711,08364.3%5.8 pCi/L
Washington County21 of 711,20361.3%5.1 pCi/L
Fillmore County22 of 7120161.2%6.2 pCi/L
Boone County23 of 7123760.8%4.7 pCi/L
Gage County24 of 7155860.2%5.2 pCi/L
Seward County25 of 7167560.0%5.2 pCi/L
Stanton County26 of 7114759.2%4.8 pCi/L
Dawes County27 of 7110258.8%4.8 pCi/L
Fillmore County radon tests by year, against Nebraska's pooled share
YearTestsAt or above 4 pCi/LMedianHighestNebraska, pooledChange from the row before
20239100.0%13.5 pCi/L25.2 pCi/L38.2%+38.9 points
20223661.1%5.3 pCi/L21.0 pCi/L34.0%+17.8 points
202118043.3%3.7 pCi/L26.6 pCi/L34.9%−22.1 points
20207865.4%6.2 pCi/L29.6 pCi/L42.2%−7.6 points
201911173.0%6.0 pCi/L20.4 pCi/L44.3%+8.3 points
201815364.7%6.1 pCi/L37.1 pCi/L44.5%+1.1 points
201713263.6%5.2 pCi/L22.3 pCi/L47.7%+2.4 points
201620161.2%6.2 pCi/L23.5 pCi/L47.4%−10.2 points
201514771.4%5.4 pCi/L33.6 pCi/L53.3%+1.4 points
20149070.0%8.1 pCi/L22.9 pCi/L50.5%First on file

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

Fillmore County, Geology

The ground under Fillmore County

Predicted

USGS's geologic map puts all of Fillmore County's mapped land in one class: high radon potential. All of it lies in the area the map calls Pre-Wisconsin glacial deposits, to which USGS gives a radon index of 13, in the high band (12 to 17).

USGS's geologic areas under Fillmore County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Pre-Wisconsin glacial depositsLoess-mantled glacial drift.High13100%

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

Fillmore County beside the ground around it

Fillmore County has more high-potential ground than Nebraska as a whole: 100% of its land against 40.9%. Of the 8 counties that border it, none has as large a share of high-potential ground; Clay County comes nearest at 100%.

Share of land by USGS radon potential: Fillmore County, the 8 counties bordering it and Nebraska
AreaEPA zoneLow potentialModerate potentialHigh potential
Fillmore CountyZone 1NoneNone100%
Clay CountyZone 1NoneNone100%
York CountyZone 1NoneNone100%
Thayer CountyZone 1NoneNone100%
Saline CountyZone 1NoneNone100%
Nuckolls CountyZone 1NoneNone100%
Seward CountyZone 1NoneNone100%
Jefferson CountyZone 1NoneNone100%
Hamilton CountyZone 1None12.6%87.4%
Nebraska93 counties, pooled by land areaVaries28.2%30.9%40.9%

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

Local help

Fillmore County, Local resources

Radon testing and mitigation in Fillmore County

What Nebraska's program says
Phone
(402) 471-1005
Licensing of radon professionals
If radon testing is done in schools, offices, or other places of work, it must be done by a licensed radon measurement business.

What it means

Fillmore County, Questions

Questions about radon in Fillmore County

Are radon levels high in Fillmore County?

In 2023, 100.0% of the radon tests reported to CDC for Fillmore County, Nebraska were at or above 4 pCi/L, and the median reported pre-mitigation result was 13.5 pCi/L. Of 71 Nebraska counties with 30 or more tests for the same period, 21 reported a higher share; pooled, the state comes to 47.4%.

Which counties border Fillmore County?

Fillmore County borders 8 counties: Clay County, York County, Thayer County, Saline County, Nuckolls County, Seward County, Jefferson County and Hamilton County.

Products

Fillmore County, Products

Testing a home in Fillmore County

In Fillmore County, 61.2% of 201 tests reported to CDC in 2016 reached 4 pCi/L, against 47.4% pooled across Nebraska. In Zone 1 the year-round level in Fillmore County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.

Test kits and monitors3

See every kit and monitor

Fillmore County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Fillmore County

Explore

Fillmore County, Bordering counties

Counties bordering Fillmore County

Calculated by Radon411

Fillmore County, Cities and towns

Cities and towns in Fillmore County

About 5,458 people live in Fillmore County by the Census Bureau's estimate for July 1, 2025, 109 fewer than in 2020 (−2.0%). Spread over its land, that is 9.5 people to the square mile. Its largest town, Geneva, has 2,100 residents, 38.5% of the total. Together its 8 incorporated places hold 73.9% of those residents; the other 26.1% live outside any of them. CDC's 201 reported tests for 2016 work out to 36.8 per 1,000 residents (2025 estimate), close to Nebraska's 33.4.

From Geneva to Strang, CDC publishes no figure by town: each reads Fillmore County's.

The cities and towns in Fillmore County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Geneva2,100−1.9%38.5%
Fairmont575−2.2%10.5%
Exeter511−2.1%9.4%
Shickley340−2.3%6.2%
Milligan244−2.4%4.5%
Ohiowa122−1.6%2.2%
Grafton108−0.9%2.0%
Strang33−2.9%0.6%

8 incorporated places, 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).

Fillmore County, Homes

Homes in Fillmore County

Fillmore County is a place of houses on their own lots: 89% of its 2,733 homes are detached single-family houses, against 72% across Nebraska. The homes are older than Nebraska's as a whole: half were built before 1958 (1975 for Nebraska), and 52% date from before 1960. Owners live in 80% of the occupied homes (Nebraska: 67%), so for most households a test and a fix are their own to order.

Homes in Fillmore County, Nebraska, 2019 to 2023
HomesFillmore CountyNebraska
Housing units2,733855,631
Detached houses89%72%
In buildings of 5 or more5%17%
Mobile homes1%3%
Built before 196052%32%
Built since 200010%22%
Middle year built19581975
Owner-occupied80%67%

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