St. Catharines Weather Forecast

Sunday December 18, 2022
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  • Tonight – Mainly cloudy with 40 percent chance of flurries. Wind west 30 km/h gusting to 50. Low minus 2. Wind chill near minus 9.
  • Monday – Cloudy. 30 percent chance of flurries late in the morning and early afternoon. Wind west 30 km/h gusting to 50. High plus 1. Wind chill minus 9 in the morning. UV index 1 or low.
  • Monday Night – Cloudy. Wind up to 15 km/h. Low minus 3. Wind chill minus 6 overnight.

St. Catharines Weather Forecast

For Wednesday June 1, 2022
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  • Tonight – A few clouds. Increasing cloudiness late this evening then 40 percent chance of showers before morning. Risk of a thunderstorm before morning. Wind southwest 20 km/h gusting to 40 becoming light early this evening. Low 19.
  • Wednesday – Mainly cloudy with 60 percent chance of showers and risk of a thunderstorm. High 23. Humidex 30. UV index 7 or high.
  • Wednesday Night – Clearing late in the evening. Wind north 30 km/h becoming light early in the evening. Low 11.

St. Catharines Weather Forecast

For Tuesday May 31, 2022
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  • Tonight – Clear. Wind southwest 30 km/h becoming light early this evening. Low 19.
  • Tuesday – Sunny. Wind becoming southwest 20 km/h gusting to 40 in the morning. High 30. Humidex 34. UV index 10 or very high.
  • Tuesday Night – Clear in the evening then partly cloudy with 40 percent chance of showers before morning. Risk of a thunderstorm before morning. Low 19.

St. Catharines Weather Forecast

For Wednesday May 25, 2022
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  • Tonight – A few clouds. Low 9.
  • Wednesday – Increasing cloudiness near noon. High 24 except 17 along the lakeshore. Humidex 26. UV index 9 or very high.
  • Wednesday Night – Partly cloudy with 30 percent chance of showers. Risk of a thunderstorm overnight. Low 15.

St. Catharines Weather Forecast

For Friday May 20, 2022
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  • Tonight – Partly cloudy. Clearing before morning. Wind south 20 km/h becoming light this evening. Low 13.
  • Friday – A mix of sun and cloud. 30 percent chance of showers late in the morning and early afternoon. Wind becoming southwest 40 km/h gusting to 60 in the morning then diminishing to 20 gusting to 40 in the afternoon. High 27. Humidex 35. UV index 9 or very high.
  • Friday Night – Mainly cloudy. Wind southwest 20 km/h gusting to 40 becoming light in the evening. Low 19.
Photo: StuartMiles - Freerange Stock

St. Catharines Weather Forecast

For Thursday May 19
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  • Tonight – Cloudy. A few showers beginning early this evening. Low 9.
  • Thursday – A few showers ending near noon then a mix of sun and cloud. Risk of a thunderstorm in the morning. Wind becoming southwest 20 km/h near noon. High 22. Humidex 25. UV index 6 or high.
  • Thursday Night – Partly cloudy. Low 14 with temperature rising to 19 by morning.
Photo: StuartMiles - Freerange Stock

St. Catharines Weather Forecast

For Wednesday May 18
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  • Tonight – Partly cloudy. Clearing this evening. Wind west 20 km/h becoming light early this evening. Low plus 4.
  • Wednesday – Sunny. Increasing cloudiness late in the morning then 40 percent chance of showers early in the afternoon. A few showers beginning in the afternoon. High 15. UV index 8 or very high.
  • Wednesday Night – A few showers ending before morning then cloudy with 40 percent chance of showers. Low 10.
Photo: StuartMiles - Freerange Stock

St. Catharines Weather Forecast

For Tuesday May 17, 2022
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  • Tonight – Showers ending early this evening then partly cloudy with 30 percent chance of showers. Risk of a thunderstorm this evening. Wind northwest 20 km/h becoming light early this evening. Wind becoming west 20 gusting to 40 after midnight. Low 9.
  • Tuesday – Mainly sunny. Increasing cloudiness late in the morning. Wind west 20 km/h gusting to 40 becoming light in the afternoon. High 18. UV index 6 or high.
  • Tuesday Night – Clearing in the evening. Low plus 4.
Photo: StuartMiles - Freerange Stock

St. Catharines Weather Forecast

For Saturday May 14, 2022
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  • Tonight – A few clouds. Low 12.
  • Saturday – A mix of sun and cloud. 30 percent chance of showers late in the afternoon with risk of a thunderstorm. High 26 except 20 near Lake Ontario. Humidex 30. UV index 8 or very high.
  • Saturday Night – Mainly cloudy. 30 percent chance of showers early in the evening with risk of a thunderstorm. Low 11.
Photo: StuartMiles - Freerange Stock

St. Catharines Weather Forecast

For Friday May 13, 2022
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  • Tonight – Clear. Low 11.
  • Friday – Mainly sunny. High 26 except 20 near Lake Ontario. Humidex 29. UV index 9 or very high.
  • Friday Night – Partly cloudy. Low 12.