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 11.7 pCi/L, based on Airthings measurements across 210 cities.

Updated August 30, 2026

Highest city

11.7pCi/L

Okauchee Lake

Wisconsin city average

3.4pCi/L

across 210 cities

Above action level

61/ 210

cities

Wisconsin Cities Ranked by Indoor Radon Levels
#	Location	Avg level	vs action level
1	Okauchee Lake	11.7 pCi/L	2.9× over
2	Barneveld	11.2 pCi/L	2.8× 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	Altoona	6.2 pCi/L	1.5× over
10	Dousman	6.2 pCi/L	1.5× over
11	Platteville	6.0 pCi/L	1.5× over
12	Salem	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	New Richmond	5.5 pCi/L	1.4× over
19	Belleville	5.5 pCi/L	1.4× over
20	Como	5.5 pCi/L	1.4× over
21	Wind Lake	5.4 pCi/L	1.4× over
22	Wausau	5.4 pCi/L	1.4× 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	Kronenwetter	5.0 pCi/L	1.3× over
30	Somerset	5.0 pCi/L	1.3× over
31	Rhinelander	4.9 pCi/L	1.2× over
32	Sussex	4.9 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	Kaukauna	4.3 pCi/L	1.1× over
49	Prescott	4.2 pCi/L	1.1× over
50	Bellevue	4.2 pCi/L	1.1× over
51	Merton	4.2 pCi/L	1.1× over
52	De Forest	4.2 pCi/L	1.0× over
53	Hartland	4.2 pCi/L	1.0× over
54	River Falls	4.2 pCi/L	1.0× over
55	Lake Geneva	4.2 pCi/L	1.0× over
56	Neenah	4.2 pCi/L	1.0× over
57	Burlington	4.1 pCi/L	1.0× over
58	Camp Lake	4.1 pCi/L	1.0× over
59	Hortonville	4.1 pCi/L	1.0× over
60	Gillett	4.1 pCi/L	1.0× over
61	North Hudson	4.1 pCi/L	1.0× over
✓ Below EPA action level (4 pCi/L)
62	Menomonie	4.0 pCi/L	1.0× under
63	Monroe	4.0 pCi/L	1.0× under
64	Mazomanie	3.9 pCi/L	1.0× under
65	Williams Bay	3.9 pCi/L	1.0× under
66	Hales Corners	3.9 pCi/L	1.0× under
67	Trempealeau	3.9 pCi/L	1.0× under
68	Wales	3.9 pCi/L	1.0× under
69	Cross Plains	3.9 pCi/L	1.0× under
70	McFarland	3.8 pCi/L	1.0× under
71	Edgerton	3.8 pCi/L	0.9× under
72	Port Washington	3.7 pCi/L	0.9× under
73	Whitewater	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	Oconomowoc	3.6 pCi/L	0.9× under
77	Pleasant Prairie	3.6 pCi/L	0.9× under
78	Franklin	3.5 pCi/L	0.9× under
79	Roberts	3.5 pCi/L	0.9× under
80	Grafton	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	Muskego	3.5 pCi/L	0.9× under
84	Westby	3.4 pCi/L	0.9× under
85	Viroqua	3.4 pCi/L	0.9× under
86	Kohler	3.4 pCi/L	0.8× under
87	Rosendale	3.4 pCi/L	0.8× under
88	East Troy	3.4 pCi/L	0.8× under
89	Rib Mountain	3.3 pCi/L	0.8× under
90	Whiting	3.3 pCi/L	0.8× under
91	Verona	3.3 pCi/L	0.8× under
92	Waukesha	3.3 pCi/L	0.8× under
93	Brooklyn	3.3 pCi/L	0.8× under
94	Antigo	3.2 pCi/L	0.8× under
95	Janesville	3.2 pCi/L	0.8× under
96	Lac du Flambeau	3.2 pCi/L	0.8× under
97	Oneida	3.1 pCi/L	0.8× under
98	Dodgeville	3.1 pCi/L	0.8× under
99	Appleton	3.1 pCi/L	0.8× under
100	Cuba City	3.1 pCi/L	0.8× under
101	Franksville	3.1 pCi/L	0.8× under
102	Hammond	3.1 pCi/L	0.8× under
103	Mequon	3.0 pCi/L	0.8× under
104	Greendale	3.0 pCi/L	0.7× under
105	Holmen	3.0 pCi/L	0.7× under
106	Black River Falls	3.0 pCi/L	0.7× under
107	Greenfield	3.0 pCi/L	0.7× under
108	Butler	2.9 pCi/L	0.7× under
109	Fitchburg	2.9 pCi/L	0.7× under
110	Stoughton	2.9 pCi/L	0.7× under
111	Prairie du Sac	2.9 pCi/L	0.7× under
112	Sturtevant	2.9 pCi/L	0.7× under
113	Mukwonago	2.9 pCi/L	0.7× under
114	New London	2.9 pCi/L	0.7× under
115	Marshfield	2.9 pCi/L	0.7× under
116	Beloit	2.8 pCi/L	0.7× under
117	Kewaskum	2.8 pCi/L	0.7× under
118	South Milwaukee	2.8 pCi/L	0.7× under
119	Lake Wazeecha	2.8 pCi/L	0.7× under
120	Oshkosh	2.8 pCi/L	0.7× under
121	La Crosse	2.8 pCi/L	0.7× under
122	Wauwatosa	2.8 pCi/L	0.7× under
123	Lannon	2.7 pCi/L	0.7× under
124	Oconto Falls	2.7 pCi/L	0.7× under
125	Waunakee	2.7 pCi/L	0.7× under
126	Brookfield	2.7 pCi/L	0.7× under
127	De Pere	2.7 pCi/L	0.7× under
128	Genoa City	2.7 pCi/L	0.7× under
129	Oostburg	2.7 pCi/L	0.7× under
130	Rothschild	2.7 pCi/L	0.7× under
131	Tomah	2.7 pCi/L	0.7× under
132	Evansville	2.7 pCi/L	0.7× under
133	Stevens Point	2.7 pCi/L	0.7× under
134	Bayside	2.6 pCi/L	0.7× under
135	Howard	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	Menomonee Falls	2.6 pCi/L	0.7× under
139	Shorewood Hills	2.6 pCi/L	0.7× under
140	Onalaska	2.6 pCi/L	0.6× under
141	Spring Green	2.6 pCi/L	0.6× under
142	Germantown	2.5 pCi/L	0.6× under
143	Racine	2.5 pCi/L	0.6× under
144	Eagle River	2.5 pCi/L	0.6× under
145	Oregon	2.5 pCi/L	0.6× under
146	Middleton	2.5 pCi/L	0.6× under
147	Cottage Grove	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	Cedarburg	2.4 pCi/L	0.6× under
154	Sherwood	2.4 pCi/L	0.6× under
155	Fond du Lac	2.4 pCi/L	0.6× under
156	Kiel	2.3 pCi/L	0.6× under
157	Hudson	2.3 pCi/L	0.6× under
158	West Bend	2.3 pCi/L	0.6× under
159	Saukville	2.3 pCi/L	0.6× under
160	Elkhorn	2.3 pCi/L	0.6× under
161	Lake Nebagamon	2.2 pCi/L	0.6× under
162	Sheboygan	2.2 pCi/L	0.6× under
163	Kenosha	2.2 pCi/L	0.6× under
164	Amery	2.2 pCi/L	0.6× under
165	Madison	2.2 pCi/L	0.6× under
166	Sturgeon Bay	2.2 pCi/L	0.6× under
167	Jackson	2.2 pCi/L	0.5× under
168	Eau Claire	2.1 pCi/L	0.5× under
169	Plover	2.1 pCi/L	0.5× under
170	Caledonia	2.1 pCi/L	0.5× under
171	Siren	2.1 pCi/L	0.5× under
172	Elm Grove	2.1 pCi/L	0.5× under
173	Little Chute	2.1 pCi/L	0.5× under
174	Shorewood	2.1 pCi/L	0.5× under
175	Ellsworth	2.1 pCi/L	0.5× under
176	Sun Prairie	2.0 pCi/L	0.5× under
177	Maple Bluff	2.0 pCi/L	0.5× under
178	Wind Point	2.0 pCi/L	0.5× under
179	Luck	2.0 pCi/L	0.5× under
180	Thiensville	2.0 pCi/L	0.5× under
181	Seymour	2.0 pCi/L	0.5× under
182	Saint Francis	1.9 pCi/L	0.5× under
183	Fox Point	1.9 pCi/L	0.5× under
184	Glendale	1.9 pCi/L	0.5× under
185	Bristol	1.9 pCi/L	0.5× under
186	Wisconsin Rapids	1.9 pCi/L	0.5× under
187	Suamico	1.9 pCi/L	0.5× under
188	Chippewa Falls	1.9 pCi/L	0.5× under
189	Hayward	1.9 pCi/L	0.5× under
190	Ashwaubenon	1.8 pCi/L	0.5× under
191	Manitowoc	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	Milton	1.7 pCi/L	0.4× under
196	Winneconne	1.7 pCi/L	0.4× under
197	Allouez	1.7 pCi/L	0.4× under
198	Fontana	1.6 pCi/L	0.4× under
199	Tomahawk	1.6 pCi/L	0.4× under
200	Waterford	1.6 pCi/L	0.4× under
201	Cudahy	1.6 pCi/L	0.4× under
202	Saint Croix Falls	1.6 pCi/L	0.4× under
203	Wisconsin Dells	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	Westfield	1.4 pCi/L	0.4× under
207	West Milwaukee	1.4 pCi/L	0.3× under
208	Kewaunee	1.3 pCi/L	0.3× under
209	Portage	1.3 pCi/L	0.3× under
210	Whitefish Bay	1.2 pCi/L	0.3× under

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