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 129 cities.

Updated August 16, 2026

Highest city

11.3pCi/L

Trentwood

Washington city average

1.4pCi/L

across 129 cities

Above action level

8/ 129

cities

Washington Cities Ranked by Indoor Radon Levels
#	Location	Avg level	Monitors	vs action level
1	Trentwood	11.3 pCi/L	7	2.8× over
2	Granite Falls	11.0 pCi/L	11	2.7× over
3	Veradale	9.3 pCi/L	15	2.3× over
4	Otis Orchards-East Farms	8.2 pCi/L	17	2.0× over
5	Millwood	7.9 pCi/L	17	2.0× over
6	Spokane Valley	5.0 pCi/L	12	1.2× over
7	Spokane	4.6 pCi/L	117	1.2× over
8	Brewster	4.2 pCi/L	7	1.1× over
✓ Below EPA action level (4 pCi/L)
9	Town and Country	3.9 pCi/L	38	1.0× under
10	Dishman	3.8 pCi/L	23	0.9× under
11	Liberty Lake	3.6 pCi/L	25	0.9× under
12	Deer Park	3.3 pCi/L	8	0.8× under
13	Lakewood	3.3 pCi/L	9	0.8× under
14	Mill Plain	3.2 pCi/L	44	0.8× under
15	Mead	3.1 pCi/L	15	0.8× under
16	Opportunity	3.1 pCi/L	12	0.8× under
17	Walnut Grove	3.1 pCi/L	13	0.8× under
18	Cle Elum	3.0 pCi/L	10	0.8× under
19	Riverbend	2.9 pCi/L	11	0.7× under
20	Fern Prairie	2.8 pCi/L	35	0.7× under
21	Pullman	2.5 pCi/L	18	0.6× under
22	Washougal	2.3 pCi/L	17	0.6× under
23	Fairwood	2.2 pCi/L	32	0.6× under
24	Vancouver	2.2 pCi/L	71	0.5× under
25	Richland	2.2 pCi/L	21	0.5× under
26	Newport	2.1 pCi/L	22	0.5× under
27	Ellensburg	1.9 pCi/L	9	0.5× under
28	Ridgefield	1.8 pCi/L	6	0.4× under
29	Orchards	1.8 pCi/L	14	0.4× under
30	White Salmon	1.7 pCi/L	11	0.4× under
31	Lake Shore	1.7 pCi/L	13	0.4× under
32	Brush Prairie	1.6 pCi/L	10	0.4× under
33	Three Lakes	1.6 pCi/L	14	0.4× under
34	Felida	1.5 pCi/L	18	0.4× under
35	Leavenworth	1.5 pCi/L	9	0.4× under
36	Peaceful Valley	1.5 pCi/L	7	0.4× under
37	La Center	1.3 pCi/L	16	0.3× under
38	Minnehaha	1.3 pCi/L	19	0.3× under
39	Covington	1.2 pCi/L	9	0.3× under
40	Bremerton	1.2 pCi/L	7	0.3× under
41	Eastgate	1.2 pCi/L	51	0.3× under
42	West Richland	1.2 pCi/L	7	0.3× under
43	Frederickson	1.2 pCi/L	7	0.3× under
44	Battle Ground	1.1 pCi/L	13	0.3× under
45	Mirrormont	1.1 pCi/L	12	0.3× under
46	Mount Vista	1.0 pCi/L	19	0.3× under
47	Maple Valley	1.0 pCi/L	9	0.3× under
48	Fall City	1.0 pCi/L	13	0.2× under
49	Olympia	1.0 pCi/L	21	0.2× under
50	Medina	0.9 pCi/L	16	0.2× under
51	Bonney Lake	0.9 pCi/L	6	0.2× under
52	Bellingham	0.9 pCi/L	22	0.2× under
53	Geneva	0.9 pCi/L	16	0.2× under
54	Maple Heights-Lake Desire	0.9 pCi/L	6	0.2× under
55	Camas	0.8 pCi/L	26	0.2× under
56	Boulevard Park	0.8 pCi/L	8	0.2× under
57	Kennewick	0.8 pCi/L	8	0.2× under
58	Blaine	0.8 pCi/L	13	0.2× under
59	West Lake Sammamish	0.8 pCi/L	32	0.2× under
60	Salmon Creek	0.7 pCi/L	6	0.2× under
61	Burien	0.7 pCi/L	9	0.2× under
62	Issaquah	0.7 pCi/L	52	0.2× under
63	Point Roberts	0.7 pCi/L	17	0.2× under
64	Bryn Mawr-Skyway	0.7 pCi/L	18	0.2× under
65	Cottage Lake	0.6 pCi/L	36	0.2× under
66	East Renton Highlands	0.6 pCi/L	17	0.2× under
67	Enetai	0.6 pCi/L	10	0.2× under
68	Kingsgate	0.6 pCi/L	32	0.2× under
69	Mercer Island	0.6 pCi/L	40	0.2× under
70	Seattle	0.6 pCi/L	516	0.2× under
71	Bellevue	0.6 pCi/L	66	0.2× under
72	Gig Harbor	0.6 pCi/L	7	0.2× under
73	Tacoma	0.6 pCi/L	14	0.2× under
74	Tanglewilde-Thompson Place	0.6 pCi/L	9	0.2× under
75	Lake Morton-Berrydale	0.6 pCi/L	8	0.2× under
76	Shoreline	0.6 pCi/L	152	0.2× under
77	White Center	0.6 pCi/L	74	0.2× under
78	West Lake Stevens	0.6 pCi/L	9	0.1× under
79	Duvall	0.6 pCi/L	14	0.1× under
80	Kenmore	0.6 pCi/L	23	0.1× under
81	Bothell	0.6 pCi/L	37	0.1× under
82	Lynden	0.6 pCi/L	7	0.1× under
83	Normandy Park	0.5 pCi/L	9	0.1× under
84	Monroe	0.5 pCi/L	7	0.1× under
85	Kirkland	0.5 pCi/L	99	0.1× under
86	Renton	0.5 pCi/L	20	0.1× under
87	Yelm	0.5 pCi/L	6	0.1× under
88	Clyde Hill	0.5 pCi/L	21	0.1× under
89	Langley	0.5 pCi/L	7	0.1× under
90	Cathcart	0.5 pCi/L	7	0.1× under
91	Federal Way	0.5 pCi/L	10	0.1× under
92	Newcastle	0.5 pCi/L	33	0.1× under
93	Bainbridge Island	0.5 pCi/L	23	0.1× under
94	Redmond	0.5 pCi/L	120	0.1× under
95	Union Hill-Novelty Hill	0.5 pCi/L	24	0.1× under
96	Ames Lake	0.4 pCi/L	13	0.1× under
97	Lake Forest Park	0.4 pCi/L	53	0.1× under
98	Meadowdale	0.4 pCi/L	12	0.1× under
99	Puyallup	0.4 pCi/L	6	0.1× under
100	Inglewood-Finn Hill	0.4 pCi/L	49	0.1× under
101	Sammamish	0.4 pCi/L	45	0.1× under
102	Fircrest	0.4 pCi/L	10	0.1× under
103	Maltby	0.4 pCi/L	6	0.1× under
104	City of Sammamish	0.4 pCi/L	68	0.1× under
105	Yarrow Point	0.4 pCi/L	28	0.1× under
106	Mukilteo	0.4 pCi/L	6	0.1× under
107	Vashon	0.4 pCi/L	6	0.1× under
108	East Hill-Meridian	0.4 pCi/L	10	0.1× under
109	Everett	0.4 pCi/L	15	0.1× under
110	Tumwater	0.4 pCi/L	10	0.1× under
111	Kingston	0.4 pCi/L	10	0.1× under
112	Woodinville	0.4 pCi/L	6	0.1× under
113	Martha Lake	0.4 pCi/L	26	0.1× under
114	Mountlake Terrace	0.4 pCi/L	6	0.1× under
115	Brier	0.3 pCi/L	9	0.1× under
116	Lynnwood	0.3 pCi/L	11	0.1× under
117	Mill Creek	0.3 pCi/L	21	0.1× under
118	Silver Firs	0.3 pCi/L	8	0.1× under
119	Alderwood Manor	0.3 pCi/L	17	0.1× under
120	Lacey	0.3 pCi/L	10	0.1× under
121	Snohomish	0.3 pCi/L	7	0.1× under
122	Camano	0.3 pCi/L	6	0.1× under
123	North Creek	0.3 pCi/L	24	0.1× under
124	Fife Heights	0.3 pCi/L	6	0.1× under
125	Marysville	0.3 pCi/L	7	0.1× under
126	Burlington	0.3 pCi/L	6	0.1× under
127	Port Orchard	0.2 pCi/L	6	0.1× under
128	Anacortes	0.2 pCi/L	7	0.0× under
129	Kent	0.2 pCi/L	6	0.0× under

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