Washington Cities Ranked by Indoor Radon Levels

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

Trentwood has the highest measured indoor radon in Washington at 11.3 pCi/L, based on Airthings measurements across 165 cities.

Updated October 19, 2026

Highest city

11.3pCi/L

Trentwood

Washington city average

1.5pCi/L

across 165 cities

Above action level

12/ 165

cities

Washington Cities Ranked by Indoor Radon Levels
#	Location	Avg level	vs action level
1	Trentwood	11.3 pCi/L	2.8× over
2	Granite Falls	10.0 pCi/L	2.5× over
3	Veradale	8.3 pCi/L	2.1× over
4	Chewelah	8.1 pCi/L	2.0× over
5	Otis Orchards-East Farms	7.9 pCi/L	2.0× over
6	Millwood	7.6 pCi/L	1.9× over
7	Airway Heights	7.4 pCi/L	1.8× over
8	Cheney	5.2 pCi/L	1.3× over
9	Spokane Valley	5.0 pCi/L	1.2× over
10	Sudden Valley	4.8 pCi/L	1.2× over
11	Davenport	4.7 pCi/L	1.2× over
12	Spokane	4.5 pCi/L	1.1× over
✓ Below EPA action level (4 pCi/L)
13	Town and Country	4.0 pCi/L	1.0× under
14	Brewster	3.9 pCi/L	1.0× under
15	Dishman	3.8 pCi/L	0.9× under
16	Oroville	3.8 pCi/L	0.9× under
17	Liberty Lake	3.5 pCi/L	0.9× under
18	Deer Park	3.3 pCi/L	0.8× under
19	Mill Plain	3.1 pCi/L	0.8× under
20	Walnut Grove	3.1 pCi/L	0.8× under
21	Lakewood	3.0 pCi/L	0.8× under
22	Mead	3.0 pCi/L	0.8× under
23	Opportunity	3.0 pCi/L	0.8× under
24	Cle Elum	2.9 pCi/L	0.7× under
25	Riverbend	2.8 pCi/L	0.7× under
26	Ephrata	2.8 pCi/L	0.7× under
27	Fern Prairie	2.7 pCi/L	0.7× under
28	Graham	2.5 pCi/L	0.6× under
29	Pullman	2.5 pCi/L	0.6× under
30	Fairwood	2.2 pCi/L	0.6× under
31	Richland	2.1 pCi/L	0.5× under
32	Vancouver	2.1 pCi/L	0.5× under
33	Medical Lake	2.1 pCi/L	0.5× under
34	Newport	2.1 pCi/L	0.5× under
35	Washougal	2.1 pCi/L	0.5× under
36	Ellensburg	1.9 pCi/L	0.5× under
37	Ridgefield	1.8 pCi/L	0.4× under
38	Hockinson	1.7 pCi/L	0.4× under
39	White Salmon	1.7 pCi/L	0.4× under
40	Lake Shore	1.7 pCi/L	0.4× under
41	Brush Prairie	1.6 pCi/L	0.4× under
42	Orchards	1.6 pCi/L	0.4× under
43	Three Lakes	1.6 pCi/L	0.4× under
44	Felida	1.5 pCi/L	0.4× under
45	Leavenworth	1.5 pCi/L	0.4× under
46	Peaceful Valley	1.5 pCi/L	0.4× under
47	Tanner	1.4 pCi/L	0.4× under
48	Rochester	1.4 pCi/L	0.4× under
49	Minnehaha	1.4 pCi/L	0.3× under
50	West Richland	1.3 pCi/L	0.3× under
51	Bremerton	1.2 pCi/L	0.3× under
52	Alderton	1.2 pCi/L	0.3× under
53	Covington	1.2 pCi/L	0.3× under
54	Frederickson	1.2 pCi/L	0.3× under
55	La Center	1.2 pCi/L	0.3× under
56	Eastgate	1.1 pCi/L	0.3× under
57	Meadow Glade	1.1 pCi/L	0.3× under
58	Mirrormont	1.1 pCi/L	0.3× under
59	Battle Ground	1.1 pCi/L	0.3× under
60	Union Hill-Novelty Hill	1.0 pCi/L	0.3× under
61	Mount Vista	1.0 pCi/L	0.2× under
62	Yelm	1.0 pCi/L	0.2× under
63	Fall City	0.9 pCi/L	0.2× under
64	Maple Valley	0.9 pCi/L	0.2× under
65	Medina	0.9 pCi/L	0.2× under
66	East Wenatchee Bench	0.9 pCi/L	0.2× under
67	Olympia	0.9 pCi/L	0.2× under
68	Bonney Lake	0.9 pCi/L	0.2× under
69	Bellingham	0.9 pCi/L	0.2× under
70	Maple Heights-Lake Desire	0.9 pCi/L	0.2× under
71	Camas	0.8 pCi/L	0.2× under
72	Boulevard Park	0.8 pCi/L	0.2× under
73	Walla Walla	0.8 pCi/L	0.2× under
74	Geneva	0.8 pCi/L	0.2× under
75	Kennewick	0.8 pCi/L	0.2× under
76	Blaine	0.8 pCi/L	0.2× under
77	Sumas	0.8 pCi/L	0.2× under
78	Elk Plain	0.7 pCi/L	0.2× under
79	East Renton Highlands	0.7 pCi/L	0.2× under
80	West Lake Sammamish	0.7 pCi/L	0.2× under
81	Tacoma	0.7 pCi/L	0.2× under
82	Burien	0.7 pCi/L	0.2× under
83	Issaquah	0.7 pCi/L	0.2× under
84	Point Roberts	0.7 pCi/L	0.2× under
85	Bellevue	0.7 pCi/L	0.2× under
86	Enetai	0.6 pCi/L	0.2× under
87	Mercer Island	0.6 pCi/L	0.2× under
88	Gig Harbor	0.6 pCi/L	0.2× under
89	Kingsgate	0.6 pCi/L	0.2× under
90	Seattle	0.6 pCi/L	0.2× under
91	Tanglewilde-Thompson Place	0.6 pCi/L	0.2× under
92	Cottage Lake	0.6 pCi/L	0.2× under
93	Shoreline	0.6 pCi/L	0.2× under
94	Bryn Mawr-Skyway	0.6 pCi/L	0.2× under
95	Lake Morton-Berrydale	0.6 pCi/L	0.2× under
96	White Center	0.6 pCi/L	0.1× under
97	West Lake Stevens	0.6 pCi/L	0.1× under
98	Salmon Creek	0.6 pCi/L	0.1× under
99	Duvall	0.6 pCi/L	0.1× under
100	Hazel Dell	0.6 pCi/L	0.1× under
101	Bothell	0.6 pCi/L	0.1× under
102	Kenmore	0.6 pCi/L	0.1× under
103	Lynden	0.6 pCi/L	0.1× under
104	Fircrest	0.5 pCi/L	0.1× under
105	Normandy Park	0.5 pCi/L	0.1× under
106	Carnation	0.5 pCi/L	0.1× under
107	Kirkland	0.5 pCi/L	0.1× under
108	Monroe	0.5 pCi/L	0.1× under
109	Five Corners	0.5 pCi/L	0.1× under
110	Renton	0.5 pCi/L	0.1× under
111	Clyde Hill	0.5 pCi/L	0.1× under
112	South Wenatchee	0.5 pCi/L	0.1× under
113	Bainbridge Island	0.5 pCi/L	0.1× under
114	Sequim	0.5 pCi/L	0.1× under
115	Chehalis	0.5 pCi/L	0.1× under
116	Langley	0.5 pCi/L	0.1× under
117	Newcastle	0.5 pCi/L	0.1× under
118	Snoqualmie	0.5 pCi/L	0.1× under
119	Cathcart	0.5 pCi/L	0.1× under
120	Federal Way	0.5 pCi/L	0.1× under
121	Des Moines	0.5 pCi/L	0.1× under
122	Ames Lake	0.4 pCi/L	0.1× under
123	Puyallup	0.4 pCi/L	0.1× under
124	Redmond	0.4 pCi/L	0.1× under
125	Inglewood-Finn Hill	0.4 pCi/L	0.1× under
126	Lake Forest Park	0.4 pCi/L	0.1× under
127	Sammamish	0.4 pCi/L	0.1× under
128	Yarrow Point	0.4 pCi/L	0.1× under
129	City of Sammamish	0.4 pCi/L	0.1× under
130	Lake Marcel-Stillwater	0.4 pCi/L	0.1× under
131	Vashon	0.4 pCi/L	0.1× under
132	East Hill-Meridian	0.4 pCi/L	0.1× under
133	Everett	0.4 pCi/L	0.1× under
134	Maltby	0.4 pCi/L	0.1× under
135	Meadowdale	0.4 pCi/L	0.1× under
136	Tumwater	0.4 pCi/L	0.1× under
137	Kingston	0.4 pCi/L	0.1× under
138	Mukilteo	0.4 pCi/L	0.1× under
139	Rosedale	0.4 pCi/L	0.1× under
140	Suquamish	0.4 pCi/L	0.1× under
141	University Place	0.4 pCi/L	0.1× under
142	Martha Lake	0.4 pCi/L	0.1× under
143	Mountlake Terrace	0.4 pCi/L	0.1× under
144	North Bend	0.4 pCi/L	0.1× under
145	Woodinville	0.4 pCi/L	0.1× under
146	Brier	0.3 pCi/L	0.1× under
147	Lynnwood	0.3 pCi/L	0.1× under
148	Alderwood Manor	0.3 pCi/L	0.1× under
149	Silver Firs	0.3 pCi/L	0.1× under
150	Mill Creek	0.3 pCi/L	0.1× under
151	Lacey	0.3 pCi/L	0.1× under
152	Snohomish	0.3 pCi/L	0.1× under
153	Lofall	0.3 pCi/L	0.1× under
154	Camano	0.3 pCi/L	0.1× under
155	Lake Stevens	0.3 pCi/L	0.1× under
156	North Creek	0.3 pCi/L	0.1× under
157	Arlington	0.3 pCi/L	0.1× under
158	Fife Heights	0.3 pCi/L	0.1× under
159	Burlington	0.3 pCi/L	0.1× under
160	Marysville	0.3 pCi/L	0.1× under
161	Orting	0.3 pCi/L	0.1× under
162	Port Orchard	0.2 pCi/L	0.1× under
163	Stanwood	0.2 pCi/L	0.0× under
164	Anacortes	0.2 pCi/L	0.0× under
165	Kent	0.2 pCi/L	0.0× under

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