Wisconsin Cities Ranked by Indoor Radon Levels

Measured averages from Airthings devices across Wisconsin, USA. Action level: 4 pCi/L — the threshold at which remediation is recommended.

Okauchee Lake has the highest measured indoor radon in Wisconsin at 11.0 pCi/L, based on Airthings measurements across 211 cities.

Updated September 28, 2026

Highest city

11.0pCi/L

Okauchee Lake

Wisconsin city average

3.4pCi/L

across 211 cities

Above action level

59/ 211

cities

Wisconsin Cities Ranked by Indoor Radon Levels
#	Location	Avg level	vs action level
1	Okauchee Lake	11.0 pCi/L	2.7× over
2	Barneveld	10.9 pCi/L	2.7× over
3	New Glarus	10.2 pCi/L	2.5× over
4	Luxemburg	9.2 pCi/L	2.3× over
5	Plymouth	7.7 pCi/L	1.9× over
6	Watertown	7.0 pCi/L	1.8× over
7	Eagle	6.9 pCi/L	1.7× over
8	Prairie du Chien	6.9 pCi/L	1.7× over
9	Salem	6.2 pCi/L	1.6× over
10	Altoona	6.2 pCi/L	1.5× over
11	Dousman	6.2 pCi/L	1.5× over
12	Platteville	6.0 pCi/L	1.5× over
13	Rice Lake	5.9 pCi/L	1.5× over
14	North Prairie	5.9 pCi/L	1.5× over
15	Lake Mills	5.8 pCi/L	1.4× over
16	Weston	5.7 pCi/L	1.4× over
17	Hartford	5.5 pCi/L	1.4× over
18	Belleville	5.5 pCi/L	1.4× over
19	Como	5.5 pCi/L	1.4× over
20	Wind Lake	5.4 pCi/L	1.4× over
21	Wausau	5.3 pCi/L	1.3× over
22	New Richmond	5.3 pCi/L	1.3× over
23	Slinger	5.3 pCi/L	1.3× over
24	North La Crosse	5.3 pCi/L	1.3× over
25	Ripon	5.3 pCi/L	1.3× over
26	Mount Horeb	5.2 pCi/L	1.3× over
27	Washburn	5.2 pCi/L	1.3× over
28	Fort Atkinson	5.1 pCi/L	1.3× over
29	Rhinelander	5.1 pCi/L	1.3× over
30	Kronenwetter	5.0 pCi/L	1.3× over
31	Somerset	5.0 pCi/L	1.3× over
32	Sussex	5.0 pCi/L	1.2× over
33	Delafield	4.8 pCi/L	1.2× over
34	Brown Deer	4.8 pCi/L	1.2× over
35	Stratford	4.7 pCi/L	1.2× over
36	Richfield	4.7 pCi/L	1.2× over
37	Mosinee	4.7 pCi/L	1.2× over
38	Somers	4.6 pCi/L	1.1× over
39	Waupun	4.6 pCi/L	1.1× over
40	Union Grove	4.6 pCi/L	1.1× over
41	Little Round Lake	4.5 pCi/L	1.1× over
42	Crandon	4.5 pCi/L	1.1× over
43	Baraboo	4.5 pCi/L	1.1× over
44	Kimberly	4.5 pCi/L	1.1× over
45	Beaver Dam	4.4 pCi/L	1.1× over
46	Big Bend	4.4 pCi/L	1.1× over
47	Richland Center	4.3 pCi/L	1.1× over
48	Merton	4.2 pCi/L	1.1× over
49	De Forest	4.2 pCi/L	1.0× over
50	Hartland	4.2 pCi/L	1.0× over
51	River Falls	4.2 pCi/L	1.0× over
52	Lake Geneva	4.2 pCi/L	1.0× over
53	Burlington	4.1 pCi/L	1.0× over
54	Hortonville	4.1 pCi/L	1.0× over
55	Kaukauna	4.1 pCi/L	1.0× over
56	Prescott	4.1 pCi/L	1.0× over
57	Gillett	4.1 pCi/L	1.0× over
58	North Hudson	4.1 pCi/L	1.0× over
59	Bellevue	4.0 pCi/L	1.0× over
✓ Below EPA action level (4 pCi/L)
60	Menomonie	4.0 pCi/L	1.0× under
61	Monroe	4.0 pCi/L	1.0× under
62	Neenah	4.0 pCi/L	1.0× under
63	Mazomanie	3.9 pCi/L	1.0× under
64	Williams Bay	3.9 pCi/L	1.0× under
65	Hales Corners	3.9 pCi/L	1.0× under
66	Trempealeau	3.9 pCi/L	1.0× under
67	Wales	3.9 pCi/L	1.0× under
68	Cross Plains	3.9 pCi/L	1.0× under
69	McFarland	3.8 pCi/L	1.0× under
70	Edgerton	3.8 pCi/L	0.9× under
71	Grafton	3.8 pCi/L	0.9× under
72	Whitewater	3.7 pCi/L	0.9× under
73	Campbellsport	3.7 pCi/L	0.9× under
74	New Berlin	3.7 pCi/L	0.9× under
75	Lake Wisconsin	3.7 pCi/L	0.9× under
76	Lac du Flambeau	3.6 pCi/L	0.9× under
77	Franklin	3.6 pCi/L	0.9× under
78	Oconomowoc	3.6 pCi/L	0.9× under
79	Pleasant Prairie	3.6 pCi/L	0.9× under
80	Roberts	3.5 pCi/L	0.9× under
81	Oak Creek	3.5 pCi/L	0.9× under
82	Wrightstown	3.5 pCi/L	0.9× under
83	Port Washington	3.5 pCi/L	0.9× under
84	Muskego	3.5 pCi/L	0.9× under
85	Waukesha	3.4 pCi/L	0.9× under
86	Westby	3.4 pCi/L	0.9× under
87	Viroqua	3.4 pCi/L	0.9× under
88	Kohler	3.4 pCi/L	0.8× under
89	Rosendale	3.4 pCi/L	0.8× under
90	East Troy	3.4 pCi/L	0.8× under
91	Brooklyn	3.3 pCi/L	0.8× under
92	Whiting	3.3 pCi/L	0.8× under
93	Rib Mountain	3.3 pCi/L	0.8× under
94	Verona	3.2 pCi/L	0.8× under
95	Antigo	3.2 pCi/L	0.8× under
96	Janesville	3.2 pCi/L	0.8× under
97	Mequon	3.1 pCi/L	0.8× under
98	Oneida	3.1 pCi/L	0.8× under
99	Dodgeville	3.1 pCi/L	0.8× under
100	Fond du Lac	3.1 pCi/L	0.8× under
101	Hammond	3.1 pCi/L	0.8× under
102	Appleton	3.0 pCi/L	0.8× under
103	Franksville	3.0 pCi/L	0.8× under
104	Holmen	3.0 pCi/L	0.8× under
105	Greendale	3.0 pCi/L	0.7× under
106	Black River Falls	3.0 pCi/L	0.7× under
107	Stoughton	3.0 pCi/L	0.7× under
108	Greenfield	3.0 pCi/L	0.7× under
109	Butler	2.9 pCi/L	0.7× under
110	Cuba City	2.9 pCi/L	0.7× under
111	Fitchburg	2.9 pCi/L	0.7× under
112	Mukwonago	2.9 pCi/L	0.7× under
113	New London	2.9 pCi/L	0.7× under
114	South Milwaukee	2.9 pCi/L	0.7× under
115	Kewaskum	2.8 pCi/L	0.7× under
116	Waunakee	2.8 pCi/L	0.7× under
117	Wauwatosa	2.8 pCi/L	0.7× under
118	Brookfield	2.8 pCi/L	0.7× under
119	Lake Wazeecha	2.8 pCi/L	0.7× under
120	Sturtevant	2.8 pCi/L	0.7× under
121	Beloit	2.8 pCi/L	0.7× under
122	Marshfield	2.8 pCi/L	0.7× under
123	Oshkosh	2.8 pCi/L	0.7× under
124	Lannon	2.7 pCi/L	0.7× under
125	Oconto Falls	2.7 pCi/L	0.7× under
126	De Pere	2.7 pCi/L	0.7× under
127	Prairie du Sac	2.7 pCi/L	0.7× under
128	La Crosse	2.7 pCi/L	0.7× under
129	Genoa City	2.7 pCi/L	0.7× under
130	Oostburg	2.7 pCi/L	0.7× under
131	Rothschild	2.7 pCi/L	0.7× under
132	Evansville	2.7 pCi/L	0.7× under
133	Howard	2.7 pCi/L	0.7× under
134	Stevens Point	2.7 pCi/L	0.7× under
135	Bayside	2.6 pCi/L	0.7× under
136	Pewaukee	2.6 pCi/L	0.7× under
137	West Salem	2.6 pCi/L	0.7× under
138	Shorewood Hills	2.6 pCi/L	0.7× under
139	Menomonee Falls	2.6 pCi/L	0.6× under
140	Onalaska	2.6 pCi/L	0.6× under
141	Racine	2.5 pCi/L	0.6× under
142	Spring Green	2.5 pCi/L	0.6× under
143	Eagle River	2.5 pCi/L	0.6× under
144	Oregon	2.5 pCi/L	0.6× under
145	Germantown	2.5 pCi/L	0.6× under
146	Tomah	2.5 pCi/L	0.6× under
147	Middleton	2.5 pCi/L	0.6× under
148	West Allis	2.5 pCi/L	0.6× under
149	Monona	2.5 pCi/L	0.6× under
150	Windsor	2.5 pCi/L	0.6× under
151	Menasha	2.4 pCi/L	0.6× under
152	River Hills	2.4 pCi/L	0.6× under
153	Cottage Grove	2.4 pCi/L	0.6× under
154	Saukville	2.4 pCi/L	0.6× under
155	Cedarburg	2.4 pCi/L	0.6× under
156	Sherwood	2.4 pCi/L	0.6× under
157	Jefferson	2.4 pCi/L	0.6× under
158	Siren	2.4 pCi/L	0.6× under
159	Hayward	2.4 pCi/L	0.6× under
160	Kiel	2.3 pCi/L	0.6× under
161	Hudson	2.3 pCi/L	0.6× under
162	West Bend	2.3 pCi/L	0.6× under
163	Madison	2.3 pCi/L	0.6× under
164	Winneconne	2.3 pCi/L	0.6× under
165	Elkhorn	2.3 pCi/L	0.6× under
166	Lake Nebagamon	2.2 pCi/L	0.6× under
167	Kenosha	2.2 pCi/L	0.6× under
168	Amery	2.2 pCi/L	0.6× under
169	Elm Grove	2.2 pCi/L	0.6× under
170	Sheboygan	2.2 pCi/L	0.6× under
171	Jackson	2.2 pCi/L	0.5× under
172	Sturgeon Bay	2.2 pCi/L	0.5× under
173	Caledonia	2.1 pCi/L	0.5× under
174	Eau Claire	2.1 pCi/L	0.5× under
175	Little Chute	2.1 pCi/L	0.5× under
176	Shorewood	2.1 pCi/L	0.5× under
177	Ellsworth	2.1 pCi/L	0.5× under
178	Plover	2.1 pCi/L	0.5× under
179	Maple Bluff	2.0 pCi/L	0.5× under
180	Sun Prairie	2.0 pCi/L	0.5× under
181	Saint Francis	2.0 pCi/L	0.5× under
182	Wind Point	2.0 pCi/L	0.5× under
183	Luck	2.0 pCi/L	0.5× under
184	Thiensville	2.0 pCi/L	0.5× under
185	Seymour	2.0 pCi/L	0.5× under
186	Fox Point	1.9 pCi/L	0.5× under
187	Glendale	1.9 pCi/L	0.5× under
188	Bristol	1.9 pCi/L	0.5× under
189	Wisconsin Rapids	1.9 pCi/L	0.5× under
190	Chippewa Falls	1.9 pCi/L	0.5× under
191	Ashwaubenon	1.8 pCi/L	0.5× under
192	Milwaukee	1.8 pCi/L	0.5× under
193	Marshall	1.8 pCi/L	0.5× under
194	Combined Locks	1.8 pCi/L	0.4× under
195	Manitowoc	1.7 pCi/L	0.4× under
196	Suamico	1.7 pCi/L	0.4× under
197	Milton	1.7 pCi/L	0.4× under
198	Allouez	1.7 pCi/L	0.4× under
199	Fontana	1.6 pCi/L	0.4× under
200	Tomahawk	1.6 pCi/L	0.4× under
201	Waterford	1.6 pCi/L	0.4× under
202	Cudahy	1.6 pCi/L	0.4× under
203	Saint Croix Falls	1.6 pCi/L	0.4× under
204	Green Bay	1.5 pCi/L	0.4× under
205	Sheboygan Falls	1.5 pCi/L	0.4× under
206	Wisconsin Dells	1.4 pCi/L	0.4× under
207	Westfield	1.4 pCi/L	0.4× under
208	West Milwaukee	1.4 pCi/L	0.3× under
209	Kewaunee	1.3 pCi/L	0.3× under
210	Portage	1.3 pCi/L	0.3× under
211	Whitefish Bay	1.2 pCi/L	0.3× under

See USA cities ranked by radon level See all States ranked by radon level