Manitoba Cities Ranked by Indoor Radon Levels
Measured averages from Airthings devices across Manitoba, Canada. Action level: 200 Bq/m³ — the threshold at which remediation is recommended.
Altona has the highest measured indoor radon in Manitoba at 428.0 Bq/m³, based on Airthings measurements across 29 cities.
Updated October 19, 2026
Highest city
428.0Bq/m³
Altona
Manitoba city average
191.4Bq/m³
across 29 cities
Above action level
10/ 29
cities
| # | Location | Avg level | vs action level |
|---|---|---|---|
| 1 | Altona | 428.0 Bq/m³ | 2.1× over |
| 2 | Carman | 324.7 Bq/m³ | 1.6× over |
| 3 | Dauphin | 323.0 Bq/m³ | 1.6× over |
| 4 | Swan River | 311.6 Bq/m³ | 1.6× over |
| 5 | Roblin | 263.5 Bq/m³ | 1.3× over |
| 6 | Morris | 225.5 Bq/m³ | 1.1× over |
| 7 | Morden | 224.0 Bq/m³ | 1.1× over |
| 8 | Portage la Prairie | 219.6 Bq/m³ | 1.1× over |
| 9 | Flin Flon | 214.8 Bq/m³ | 1.1× over |
| 10 | Winkler | 200.2 Bq/m³ | 1.0× over |
| ✓ Below EPA action level (200 Bq/m³) | |||
| 11 | Killarney | 199.7 Bq/m³ | 1.0× under |
| 12 | Boissevain | 187.7 Bq/m³ | 0.9× under |
| 13 | Brandon | 186.8 Bq/m³ | 0.9× under |
| 14 | Stonewall | 185.4 Bq/m³ | 0.9× under |
| 15 | Selkirk | 184.0 Bq/m³ | 0.9× under |
| 16 | Minnedosa | 180.8 Bq/m³ | 0.9× under |
| 17 | Niverville | 179.8 Bq/m³ | 0.9× under |
| 18 | Gimli | 178.7 Bq/m³ | 0.9× under |
| 19 | Carberry | 170.9 Bq/m³ | 0.9× under |
| 20 | Headingley | 166.7 Bq/m³ | 0.8× under |
| 21 | Lac du Bonnet | 155.5 Bq/m³ | 0.8× under |
| 22 | Winnipeg | 149.1 Bq/m³ | 0.7× under |
| 23 | Rivers | 139.2 Bq/m³ | 0.7× under |
| 24 | Beausejour | 124.6 Bq/m³ | 0.6× under |
| 25 | Neepawa | 116.0 Bq/m³ | 0.6× under |
| 26 | Steinbach | 110.3 Bq/m³ | 0.6× under |
| 27 | Virden | 105.6 Bq/m³ | 0.5× under |
| 28 | La Broquerie | 63.8 Bq/m³ | 0.3× under |
| 29 | Thompson | 31.2 Bq/m³ | 0.2× under |