Manitoba Radon Map: Every Home Health Canada Tested, and What It Read

1,186 homes across Manitoba were long-term tested for radon in the two federal surveys. Every one is a dot on this map, coloured by what it read, with the number of tested homes printed beside every district figure.

The Map

Every dot is one tested house. Zoom in for street names. Shaded districts had no home tested in either survey.

under 100100 to 147148 to 199200 and aboveno homes tested

1,186 measurements shown. Dot positions inside a district are illustrative, not addresses. The survey records which district a home was in, never where it stood. Tap any dot for its reading, or any district for its count and median. Rural districts here cover thousands of square kilometres, so a dot in one says very little about any particular corner of it.

Built from Health Canada's published measurements under the Open Government Licence. We do not sell radon testing or mitigation.

What the Numbers Say

27%

of tested Manitoba homes at or above Canada's 200 Bq/m³ action level

114

median reading, Bq/m³

1,903

highest single reading, in R7N

Manitoba sits 2nd of the 33 places mapped with a hundred or more tested homes, at 27.0% at or above the action level, between Halifax at 35.2% and Toronto and the GTA at 2.2%. All on the same two surveys and the same method. The spread between places is real, and the spread between houses on one street is bigger still.

The Number Changes Depending on Whose Limit You Use

Canada acts at 200 Bq/m³. The United States EPA acts at about 148. The World Health Organization sets a reference level of 100. Applied to the same 1,186 homes:

27%

at or above Canada's 200

38%

at or above the US EPA's 148

56%

at or above the WHO's 100

Same houses, same measurements. Why the three numbers differ, and which one to use.

By Postal District, with the Sample Sizes Shown

Read the count column before the median column. A district resting on four houses is a hint, not a verdict, and those rows are greyed. The land area column matters too: a district covering ten thousand square kilometres is an average across a region, not a neighbourhood.

District	Land km²	Homes tested	Median	Highest	At or over 200
R6M	411	13	408	1226	10
R2M	15	7	331	1220	5
R2H	6	3	294	411	3
R7N	1,116	31	290	1903	23
R2K	11	6	285	635	3
R3K	6	2	249	462	1
R3R	16	8	244	799	5
R2P	17	6	238	353	5
R0K	12,816	46	204	1296	23
R6W	461	4	193	457	2
R3T	24	9	191	398	4
R3L	5	3	190	405	1
R3W	7	4	190	282	2
R1N	789	26	176	405	12
R7A	633	26	157	576	11
R2X	9	4	155	372	1
R0G	9,686	50	152	1583	20
R2G	16	10	152	234	3
R2N	38	5	151	204	1
R3G	7	4	148	188	0
R3P	19	13	140	373	3
R3E	7	2	138	238	1
R1A	433	21	136	546	6
R0J	13,598	46	134	1076	18
R2E	42	3	130	139	0
R2R	17	2	128	180	0
R0H	7,212	11	125	346	3
R0L	52,618	81	125	915	29
R7C	10	2	125	232	1
R4K	285	2	122	163	0
R3Y	18	3	121	195	0
R7B	15	33	121	766	13
R2V	19	6	117	330	2
R0C	39,343	72	109	545	22
R3J	13	7	109	283	2
R3B	2	3	107	139	0
R3X	18	2	107	114	0
R3N	8	5	105	199	0
R5G	215	32	102	286	3
R5H	163	13	101	218	1
R9A	781	72	99	523	9
R0E	13,766	116	97	636	22
R3V	28	3	97	675	1
R2C	24	9	96	435	2
R3M	7	6	94	742	2
R0M	11,233	38	92	413	8
R0B	365,303	72	90	1122	15
R2J	29	6	89	258	1
R2W	7	3	80	82	0
R8A	13	62	80	382	5
R0A	6,747	53	79	507	7
R2L	5	5	70	182	0
R8N	16	115	39	479	9

23 districts have ten or more tested homes, which is where these figures start to mean something. The districts with no measurement at all are R1B, R1C, R2Y, R3A, R3C, R3H, R3S, R4A, R4G, R4H, R4J, R4L, R5A, R5J, R5K, R5L, R5M, R5N, R5P, R5R, R5T.

What Actually Settles It

Nothing on this page describes your house. Radon varies enormously between homes on the same street, because it depends on how each building sits on and draws air from the ground beneath it. The highest reading here is 1,903 Bq/m³ and it sits in a district whose median is far below it. A long-term test in your own home is the only measurement that tells you anything about your home.

Also: every C-NRPP certified radon company here, the other city and province maps, and what radon actually is.

Sources and method. Radon measurements: Health Canada, Radon and Thoron Data From Canadian Homes (Winnipeg CMA) pooled with the Cross-Canada Survey of Radon Concentrations in Homes 2009-2011, both under the Open Government Licence – Canada. Boundaries: Statistics Canada 2021 cartographic forward sortation area file, same licence. Percentages are calculated from the individual measurements shown, not quoted from a summary. Land areas are from the Statistics Canada boundary file.