Maryland Cities Ranked by Indoor Radon Levels

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

La Vale has the highest measured indoor radon in Maryland at 10.2 pCi/L, based on Airthings measurements across 202 cities.

Updated October 19, 2026

Highest city

10.2pCi/L

La Vale

Maryland city average

2.6pCi/L

across 202 cities

Above action level

25/ 202

cities

Maryland Cities Ranked by Indoor Radon Levels
#	Location	Avg level	vs action level
1	La Vale	10.2 pCi/L	2.6× over
2	Williamsport	10.1 pCi/L	2.5× over
3	Hancock	7.7 pCi/L	1.9× over
4	Manchester	7.5 pCi/L	1.9× over
5	Saint James	7.2 pCi/L	1.8× over
6	Green Valley	7.1 pCi/L	1.8× over
7	Boonsboro	6.1 pCi/L	1.5× over
8	Urbana	6.0 pCi/L	1.5× over
9	Mount Airy	5.9 pCi/L	1.5× over
10	Bartonsville	5.3 pCi/L	1.3× over
11	Wilson-Conococheague	5.1 pCi/L	1.3× over
12	Londontowne	4.9 pCi/L	1.2× over
13	Keedysville	4.8 pCi/L	1.2× over
14	Huntingtown	4.8 pCi/L	1.2× over
15	Walkersville	4.8 pCi/L	1.2× over
16	Westminster	4.6 pCi/L	1.1× over
17	Friendly	4.5 pCi/L	1.1× over
18	Robinwood	4.5 pCi/L	1.1× over
19	Davidsonville	4.5 pCi/L	1.1× over
20	Chesapeake Beach	4.3 pCi/L	1.1× over
21	Maugansville	4.3 pCi/L	1.1× over
22	Chesapeake Ranch Estates	4.2 pCi/L	1.0× over
23	Paramount-Long Meadow	4.2 pCi/L	1.0× over
24	Dunkirk Town Center	4.1 pCi/L	1.0× over
25	New Windsor	4.0 pCi/L	1.0× over
✓ Below EPA action level (4 pCi/L)
26	Bel Air North	4.0 pCi/L	1.0× under
27	Kingsville	4.0 pCi/L	1.0× under
28	Frostburg	3.8 pCi/L	1.0× under
29	Mellwood	3.8 pCi/L	1.0× under
30	Pikesville	3.8 pCi/L	0.9× under
31	Hughesville	3.7 pCi/L	0.9× under
32	Hagerstown	3.7 pCi/L	0.9× under
33	Spencerville	3.7 pCi/L	0.9× under
34	Hampstead	3.7 pCi/L	0.9× under
35	Fairland	3.6 pCi/L	0.9× under
36	Hunt Valley	3.6 pCi/L	0.9× under
37	Oakland	3.6 pCi/L	0.9× under
38	Langley Park	3.6 pCi/L	0.9× under
39	Naval Academy	3.6 pCi/L	0.9× under
40	La Plata	3.5 pCi/L	0.9× under
41	Crownsville	3.5 pCi/L	0.9× under
42	Huntingtown Town Center	3.5 pCi/L	0.9× under
43	Randallstown	3.5 pCi/L	0.9× under
44	Colesville	3.5 pCi/L	0.9× under
45	Ashton-Sandy Spring	3.4 pCi/L	0.9× under
46	Dunkirk	3.4 pCi/L	0.8× under
47	Cape Saint Claire	3.4 pCi/L	0.8× under
48	Elkton	3.4 pCi/L	0.8× under
49	Sykesville	3.4 pCi/L	0.8× under
50	Calverton	3.3 pCi/L	0.8× under
51	Taneytown	3.3 pCi/L	0.8× under
52	Highland	3.3 pCi/L	0.8× under
53	Garrison	3.2 pCi/L	0.8× under
54	Clover Hill	3.2 pCi/L	0.8× under
55	Mountain Lake Park	3.2 pCi/L	0.8× under
56	Deale	3.1 pCi/L	0.8× under
57	Owings	3.1 pCi/L	0.8× under
58	Brunswick	3.1 pCi/L	0.8× under
59	Damascus	3.1 pCi/L	0.8× under
60	Upper Marlboro	3.1 pCi/L	0.8× under
61	Cumberland	3.1 pCi/L	0.8× under
62	Burtonsville	3.1 pCi/L	0.8× under
63	Bel Air	3.1 pCi/L	0.8× under
64	Aberdeen	3.0 pCi/L	0.8× under
65	Hillsmere Shores	3.0 pCi/L	0.7× under
66	Kemp Mill	3.0 pCi/L	0.7× under
67	Mays Chapel	3.0 pCi/L	0.7× under
68	Fort Washington	3.0 pCi/L	0.7× under
69	Lutherville	3.0 pCi/L	0.7× under
70	White Oak	2.9 pCi/L	0.7× under
71	Annapolis	2.9 pCi/L	0.7× under
72	Eldersburg	2.9 pCi/L	0.7× under
73	Leonardtown	2.9 pCi/L	0.7× under
74	Adamstown	2.9 pCi/L	0.7× under
75	Columbia	2.9 pCi/L	0.7× under
76	Prince Frederick	2.8 pCi/L	0.7× under
77	Rising Sun	2.8 pCi/L	0.7× under
78	Linganore	2.8 pCi/L	0.7× under
79	Gambrills	2.8 pCi/L	0.7× under
80	Jarrettsville	2.8 pCi/L	0.7× under
81	Arnold	2.6 pCi/L	0.7× under
82	Mechanicsville	2.6 pCi/L	0.7× under
83	Frederick	2.6 pCi/L	0.7× under
84	Hillandale	2.6 pCi/L	0.7× under
85	Savage	2.6 pCi/L	0.7× under
86	Owings Mills	2.5 pCi/L	0.6× under
87	Fulton	2.5 pCi/L	0.6× under
88	Darnestown	2.5 pCi/L	0.6× under
89	Smithsburg	2.5 pCi/L	0.6× under
90	Derwood	2.4 pCi/L	0.6× under
91	Rosedale	2.4 pCi/L	0.6× under
92	Bel Air South	2.4 pCi/L	0.6× under
93	Riviera Beach	2.4 pCi/L	0.6× under
94	Glenn Dale	2.4 pCi/L	0.6× under
95	Riverside	2.4 pCi/L	0.6× under
96	Reisterstown	2.3 pCi/L	0.6× under
97	Ellicott City	2.3 pCi/L	0.6× under
98	Point of Rocks	2.3 pCi/L	0.6× under
99	Catonsville	2.3 pCi/L	0.6× under
100	North Laurel	2.3 pCi/L	0.6× under
101	Myersville	2.2 pCi/L	0.6× under
102	Charlestown	2.2 pCi/L	0.5× under
103	Odenton	2.2 pCi/L	0.5× under
104	Parole	2.2 pCi/L	0.5× under
105	Bowie	2.2 pCi/L	0.5× under
106	California	2.2 pCi/L	0.5× under
107	Cockeysville	2.2 pCi/L	0.5× under
108	Potomac	2.2 pCi/L	0.5× under
109	Germantown	2.1 pCi/L	0.5× under
110	Rockville	2.1 pCi/L	0.5× under
111	Fallston	2.1 pCi/L	0.5× under
112	Severna Park	2.1 pCi/L	0.5× under
113	Timonium	2.1 pCi/L	0.5× under
114	North Beach	2.0 pCi/L	0.5× under
115	North Kensington	2.0 pCi/L	0.5× under
116	Brookmont	2.0 pCi/L	0.5× under
117	Crofton	2.0 pCi/L	0.5× under
118	Chestertown	2.0 pCi/L	0.5× under
119	Carney	2.0 pCi/L	0.5× under
120	Forest Glen	2.0 pCi/L	0.5× under
121	Redland	2.0 pCi/L	0.5× under
122	Linthicum	1.9 pCi/L	0.5× under
123	Woodlawn	1.9 pCi/L	0.5× under
124	Lexington Park	1.9 pCi/L	0.5× under
125	South Bel Air	1.9 pCi/L	0.5× under
126	Arden on the Severn	1.9 pCi/L	0.5× under
127	Clarksburg	1.9 pCi/L	0.5× under
128	Jefferson	1.9 pCi/L	0.5× under
129	Riva	1.9 pCi/L	0.5× under
130	Herald Harbor	1.9 pCi/L	0.5× under
131	Hyattsville	1.9 pCi/L	0.5× under
132	Four Corners	1.9 pCi/L	0.5× under
133	Saint Charles	1.8 pCi/L	0.5× under
134	Cabin John	1.8 pCi/L	0.5× under
135	Spring Ridge	1.8 pCi/L	0.5× under
136	Kensington	1.8 pCi/L	0.4× under
137	Glen Burnie	1.8 pCi/L	0.4× under
138	Towson	1.8 pCi/L	0.4× under
139	Middletown	1.7 pCi/L	0.4× under
140	North Potomac	1.7 pCi/L	0.4× under
141	Ilchester	1.7 pCi/L	0.4× under
142	Jessup	1.7 pCi/L	0.4× under
143	Somerset	1.7 pCi/L	0.4× under
144	Brock Hall	1.6 pCi/L	0.4× under
145	Rossmoor	1.6 pCi/L	0.4× under
146	Perry Hall	1.6 pCi/L	0.4× under
147	Silver Spring	1.6 pCi/L	0.4× under
148	Travilah	1.6 pCi/L	0.4× under
149	Pleasant Hills	1.6 pCi/L	0.4× under
150	Chevy Chase	1.6 pCi/L	0.4× under
151	Havre de Grace	1.6 pCi/L	0.4× under
152	Montgomery Village	1.6 pCi/L	0.4× under
153	Wheaton	1.6 pCi/L	0.4× under
154	West Elkridge	1.6 pCi/L	0.4× under
155	Olney	1.6 pCi/L	0.4× under
156	Bethesda	1.5 pCi/L	0.4× under
157	Laurel	1.5 pCi/L	0.4× under
158	Hampton	1.5 pCi/L	0.4× under
159	Lake Shore	1.5 pCi/L	0.4× under
160	Waldorf	1.5 pCi/L	0.4× under
161	North Bethesda	1.4 pCi/L	0.4× under
162	Middle River	1.4 pCi/L	0.4× under
163	Pasadena	1.4 pCi/L	0.4× under
164	South Kensington	1.4 pCi/L	0.4× under
165	Friendship Village	1.4 pCi/L	0.4× under
166	Poolesville	1.4 pCi/L	0.4× under
167	Braddock Heights	1.4 pCi/L	0.3× under
168	Takoma Park	1.4 pCi/L	0.3× under
169	Layhill	1.4 pCi/L	0.3× under
170	White Marsh	1.4 pCi/L	0.3× under
171	Hillcrest Heights	1.4 pCi/L	0.3× under
172	Maryland City	1.3 pCi/L	0.3× under
173	North East	1.3 pCi/L	0.3× under
174	Severn	1.3 pCi/L	0.3× under
175	Baltimore	1.3 pCi/L	0.3× under
176	Brooklyn Park	1.3 pCi/L	0.3× under
177	Gaithersburg	1.2 pCi/L	0.3× under
178	Chevy Chase Village	1.2 pCi/L	0.3× under
179	Glenmont	1.2 pCi/L	0.3× under
180	South Gate	1.2 pCi/L	0.3× under
181	Ballenger Creek	1.2 pCi/L	0.3× under
182	Chillum	1.1 pCi/L	0.3× under
183	Bowleys Quarters	1.1 pCi/L	0.3× under
184	University Park	1.1 pCi/L	0.3× under
185	Bennsville	1.1 pCi/L	0.3× under
186	Aspen Hill	1.1 pCi/L	0.3× under
187	Cloverly	1.1 pCi/L	0.3× under
188	South Laurel	1.0 pCi/L	0.3× under
189	Oxon Hill	1.0 pCi/L	0.3× under
190	West Laurel	1.0 pCi/L	0.2× under
191	Green Haven	0.9 pCi/L	0.2× under
192	Parkville	0.9 pCi/L	0.2× under
193	Mount Rainier	0.9 pCi/L	0.2× under
194	Chester	0.8 pCi/L	0.2× under
195	Elkridge	0.8 pCi/L	0.2× under
196	Hanover	0.8 pCi/L	0.2× under
197	Fort Meade	0.7 pCi/L	0.2× under
198	Brandywine	0.7 pCi/L	0.2× under
199	Milford Mill	0.5 pCi/L	0.1× under
200	Lansdowne	0.5 pCi/L	0.1× under
201	College Park	0.4 pCi/L	0.1× under
202	Dundalk	0.3 pCi/L	0.1× under

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