Weather St. Catharines, ON 17°C : °C Clear : 0km/h N : 101.7 kPa : 16°C : 94% : 14°C / : 22°C Tuesday morning 18°C Light rain Tuesday afternoon 22°C Light rain Tuesday evening 20°C Cloudy with showers 22°C : 70% 19°C : 20% 20°C : 10% 20°C : 0%