Two readings composited together from the Purpleair site showing the reading at a specific spot in Winnipeg on August 7th at 2:37 PM On the left is the Environment Canada scale showing 28 (out of ten) "10 minute Average Canadian PM2.5 (AQHI+) is now 10+: Reduce or reschedule strenuous activities outdoors, especially if you experience symptoms such as coughing and throat irritation. Avoid strenuous activities outdoors. Children and the elderly should also avoid outdoor physical exertion." Right side shows a reading of 327 "10 minute Average US EPA PM2.5 (AQI) is now >300: Health warning of emergency conditions: everyone is more likely to be affected with 24 hours of exposure."