Hot and humid weather prompted a special air quality statement for Waterloo Region, Guelph, Erin, and Southern Wellington County.
Environment Canada issued the statement on Saturday and say the conditions created elevated pollution levels.
By Sunday, the statement was no longer in effect.
Hot and sunny conditions were expected to increase ground-level ozone concentrations and cause moderate risk AQHI (Air Quality Health Index) values throughout the day. Short-term high risk AQHI values were also possible in the afternoon.
The agency says people may experience symptoms like coughing, throat irritation, headaches, or shortness of breath during a special air quality statement.
Anyone experiencing symptoms is advised to reduce any strenuous outdoor activities.
Children, seniors, those with cardiovascular or lung disease like asthma, those with heart problems, and those with diabetes are especially at risk.
A similar statement was also in effect for Huron-Perth.
