Is radon high in Milwaukee, Wisconsin?

Low. Averaging the model's ZIP-code predictions across Milwaukee (weighted by how much of the city each ZIP covers) gives a long-term basement mean of 1.2 pCi/L - about 32% below the US average of 1.8 and about 39% below the Wisconsin average of 2.0. That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Milwaukee ranks 13 of 15 Wisconsin cities on this site.

What do actual radon tests show around Milwaukee?

Wisconsin Department of Health Services publishes results for Milwaukee County (not the city alone) covering 1995-2016 (9,209 tests): an average of 5.1 pCi/L, 48.9% of results at or above the 4 pCi/L action level. These are voluntary home tests, so they skew toward basements and toward homes where radon was suspected; the model's predicted basement average for Milwaukee is 1.2 pCi/L.

Which Milwaukee ZIP codes have the highest radon?

Predictions for the 23 modeled ZIP codes in Milwaukee range from 1.0 to 2.0 pCi/L in the basement. 0% of them are predicted at or above 4 pCi/L and 0% at or above 2. That spread is why the ZIP table below matters more than the city-wide number.

Should I test for radon in Milwaukee?

Yes, once. The EPA recommends testing every home regardless of area. A short-term kit costs little and settles the question for your house; Milwaukee's low predicted average describes the typical home, not yours.

What does EPA Radon Zone 2 mean for Milwaukee?

Milwaukee sits mainly in Milwaukee County, which the EPA classifies as Zone 2 - moderate potential (2-4 pCi/L). The zone map dates from 1993 and covers whole counties. The newer model's city average of 1.2 pCi/L does not line up with Zone 2, which is common - the EPA itself says high-radon homes exist in every zone. Neither replaces a test of your own home.

Radon levels in Milwaukee, Wisconsin

LowEPA Zone 2

Predicted long-term basement average of 1.2 pCi/L (model estimate) across the 23 modeled ZIP codes in Milwaukee - about 32% below the US average of 1.8, about 39% below the Wisconsin average of 2.0. Ranked #13 of 15 Wisconsin cities on this site. Most of the city lies in Milwaukee County.

Test Milwaukee, WI once anyway - radon varies house to house

The predicted basement average here is 1.2 pCi/L, below the EPA's 2 pCi/L "consider fixing" threshold. That's good news for the area - but the EPA still recommends every home be tested, because foundation cracks, soil pockets and ventilation make one house very different from its neighbor. One inexpensive kit settles it.

Get a short-term test kit →Or track it with a continuous monitor

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Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. Measured state test results are shown separately below, labeled with their source and years. How the numbers work.

1.2 ± 0.09

pCi/L predicted basement mean (model SD)

0.8 ± 0.09

pCi/L predicted upstairs (above-ground) mean

1.0-2.0

range of ZIP-level basement predictions in the city

of Milwaukee ZIPs predicted ≥ 4 pCi/L (0% ≥ 2)

Measured radon tests in Milwaukee County (Wisconsin Department of Health Services, 1995-2016)

Actual results from home radon tests reported to the state, separate from the model estimate above. Coverage: 1995-2016.

Measured mean: 5.1 pCi/L
Results ≥ 4 pCi/L: 48.9%
Results ≥ 2 pCi/L: 73.2%
Sample: 9,209 tests

Figure	Model (predicted)	State tests (measured)
Mean, pCi/L	1.3 basement	5.1
Share ≥ 4 pCi/L	not a model output	48.9%

The measured mean runs 3.9 pCi/L above the model because state test data is voluntary and skews toward basements, winter, and homeowners who already suspected a problem, while the model estimates the long-term average across all homes.

Source: Wisconsin Indoor Radon Test Results (Wisconsin Radon Map Service, layer 3), Wisconsin Department of Health Services. No license statement on the public feature service. Method and download.

What this means for Milwaukee

The typical Milwaukee home is predicted below 2 pCi/L, the lowest band. That describes the average house; the ZIP-level predictions inside the city still span 1.0 to 2.0 pCi/L.

The city figure is not a separate estimate: it is the mean of the model's ZIP-code predictions, weighted by the share of the city's land in each ZIP (Census 2020 ZCTA-to-place relationship file). Note that the EPA classifies Milwaukee County as Zone 2 while the newer model predicts 1.2 pCi/L for Milwaukee; where they disagree, we grade on the model but show both.

Comparable Wisconsin cities: West Allis (1.2), Sheboygan (1.2), Waukesha (1.4), Wauwatosa (1.4).

ZIP codes in Milwaukee

ZIPs that overlap the city, largest share of its land first. Predicted basement and upstairs means are model estimates; ZIPs the model does not cover show a dash.

ZIP	Share of city	Basement	Upstairs	Grade
53224	11%	1.6 ± 0.06	1.0	Low
53207	11%	1.3 ± 0.10	0.7	Low
53209	7%	1.1 ± 0.11	0.8	Low
53223	7%	1.3 ± 0.12	0.8	Low
53221	7%	1.3 ± 0.09	1.0	Low
53218	6%	1.1 ± 0.07	0.6	Low
53225	6%	1.2 ± 0.10	0.9	Low
53215	6%	1.1 ± 0.12	0.6	Low
53216	5%	1.0 ± 0.16	0.6	Low
53208	5%	1.1 ± 0.08	0.5	Low
53212	4%	1.3 ± 0.09	0.7	Low
53204	3%	1.1 ± 0.07	0.6	Low
53222	3%	1.2 ± 0.09	0.8	Low
53206	3%	1.3 ± 0.11	0.5	Low
53219	3%	1.0 ± 0.10	0.7	Low
53210	3%	1.1 ± 0.08	0.7	Low
53202	2%	1.0 ± 0.07	0.5	Low
53211	2%	1.4 ± 0.07	0.7	Low
53214	2%	1.2 ± 0.09	0.8	Low
53233	2%	1.1 ± 0.07	0.6	Low
53220	2%	2.0 ± 0.10	1.0	Low
53205	2%	1.2 ± 0.06	0.6	Low
53203	1%	1.1 ± 0.07	0.6	Low
53295	<1%	—	—	no model

Testing help in Wisconsin

Wisconsin's radon program page is at www.dhs.wisconsin.gov; it lists testing and certified-mitigator guidance. EPA state radon contacts page. If a test comes back at 4 pCi/L or higher, mitigation typically costs $800-$2,500 installed; use EPA find-a-professional and read the mitigation guide.

Milwaukee radon questions

Is radon high in Milwaukee, Wisconsin?: Low. Averaging the model's ZIP-code predictions across Milwaukee (weighted by how much of the city each ZIP covers) gives a long-term basement mean of 1.2 pCi/L - about 32% below the US average of 1.8 and about 39% below the Wisconsin average of 2.0. That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Milwaukee ranks 13 of 15 Wisconsin cities on this site.
What do actual radon tests show around Milwaukee?: Wisconsin Department of Health Services publishes results for Milwaukee County (not the city alone) covering 1995-2016 (9,209 tests): an average of 5.1 pCi/L, 48.9% of results at or above the 4 pCi/L action level. These are voluntary home tests, so they skew toward basements and toward homes where radon was suspected; the model's predicted basement average for Milwaukee is 1.2 pCi/L.
Which Milwaukee ZIP codes have the highest radon?: Predictions for the 23 modeled ZIP codes in Milwaukee range from 1.0 to 2.0 pCi/L in the basement. 0% of them are predicted at or above 4 pCi/L and 0% at or above 2. That spread is why the ZIP table below matters more than the city-wide number.
Should I test for radon in Milwaukee?: Yes, once. The EPA recommends testing every home regardless of area. A short-term kit costs little and settles the question for your house; Milwaukee's low predicted average describes the typical home, not yours.
What does EPA Radon Zone 2 mean for Milwaukee?: Milwaukee sits mainly in Milwaukee County, which the EPA classifies as Zone 2 - moderate potential (2-4 pCi/L). The zone map dates from 1993 and covers whole counties. The newer model's city average of 1.2 pCi/L does not line up with Zone 2, which is common - the EPA itself says high-radon homes exist in every zone. Neither replaces a test of your own home.

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